The area was about 25 miles (40km) wide (north to south) and 100 miles (160km) long, covering an estimated 1,500 square miles (4,000km2); other estimates put the area of the swamp at 6,700 square kilometres (2,600sqmi).[3][4] The Ohio Department of Natural Resources in 1988 stated that the Swamp covered 3,072,000 acres (1,243,194 ha) and was drained between 1859 and 1885.[5]
The land once covered by the Swamp lies primarily within the Maumee, Ottawa, Portage, and Sanduskywatersheds. Its boundary was determined by ancient sandy beach ridges formed on the proglacial lake shores, after glacial retreat several thousand years ago. It stretched roughly from Fort Wayne, Indiana, eastward to the Ottawa National Wildlife Refuge along the Lake Erie shore.[8]
The vast Swamp was a network of forests, wetlands, and grasslands. In the lowest, flattest areas, prone to permanent inundation, deciduous swamp forests predominated, characterized especially by species of ash, elm, cottonwood and sycamore. In slightly higher areas with some topographic relief and better drainage, beech, maples, basswood, tuliptree and other more mesic species were dominant. On elevated beach ridges and moraines with good to excessive drainage, more xeric species, especially oak and hickory, were dominant. The area contained non-forested wetlands, particularly marsh and wet prairies, with marshes being particularly extensive along the Lake Erie shoreline east of Toledo.
The Laurentide ice sheet covered northwest Ohio during the Last Glacial Period. The ice sheet was, by one estimate, at least 300 to 500 meters high (984 to 1,640 feet high) in some places around the Great Lakes, and as high as 1,200 meters (3,937 feet) around Hudson Bay and Quebec.[10] Other estimates place the height of the ice sheet as high as two miles in other areas. Lake Maumee developed within the ice sheet's footprint after the ice sheet gradually retreated out of northwest Ohio about 24,000 years ago. The Maumee Torrent was a catastrophic draining of Lake Maumee 14,000 to 17,000 years Before Present, or BP. This mega-flood and the ice sheet shaped the landscape in ways that can be seen in present-day Lidar-based digital elevation model (DEM) imagery of northwest Ohio.
After the Maumee mega-flood about 14,000 years BP, Lake Arkona formed and existed in northwest Ohio until 13,600 years BP, followed by other proglacial lakes that formed with each subsequent drop in water elevations: Lake Ypsilanti (13,600-13,000 years BP); Lake Whittlesey (13,000-12,800 years BP); Lake Warren and Lake Wayne (12,800-12,500 years BP); Lake Grassmere and Lake Lundy (12,500-12,400 years BP); Early Lake Erie (12,400-8,000 years BP); Middle Lake Erie (8,000-4,000 years BP); and finally Modern Lake Erie (4,000 years BP to the present).[11] Between 9,000 and 4,000 years BP, a slow uplift of the Earth's crust, called isosatic rebound, occurred in northwest Ohio due to the gradual removal of the weight from the ice sheet that had receded. Isostatic rebound impacted the region's hydrology, and changed the course of surface waters. The highest proglacial lake levels were about 220 feet (67 M) above current Lake Erie levels. Lake drainage escaped to the west during higher and earlier lake stages, and then to the east with later and lower lake stages, until Lake Erie became the first of the Great Lakes to reach its present and familiar outline.[12]
The Great Black Swamp developed over time on the former proglacial lake beds across northwest Ohio in the Huron-Erie Lake Plain, which consists of the Maumee Lake Plains, the Oak Openings, the Paulding Plains, and the Marblehead Drift/Limestone Plain.[13] The Huron-Erie Lake Plain is a lacustrine plain covered with clay-rich till between 15,000 and 13,000 years BP. Its Devonian bedrock is expressed as dark, dense shale. Limestone, covered by 20 to 80 feet (6 to 24 meters) of till, can be found south of the Maumee River, while the north of the Maumee River consists of glacial drift, 90 feet (27 meters) thick, over shale bedrock.[14] Clay leaching from weathered shale created fine-grain sediment along the moraine that runs through what is now the city of Defiance. Aeolian sand dunes were deposited across the plain. The clay, till, and organic soil retained water throughout the year, and the ice sheet created depressions and "kettle holes" which accumulated peat and decayed vegetation.[15] Ancient fluvial deposits of lacustrine sands over diamicton contained organic-rich sand. From these geological findings, one study concluded the glacial lake that preceded the Swamp did not have a traditional beach, but instead had a chain of islands for a shoreline. It also studied how lake levels changed before the warm Bølling-Allerød Interstadial 14,690 to 12,890 years BP.[16] This time period is associated with Meltwater pulse 1A, when global sea levels rose between 16 meters (52 feet) and 25 meters (82 feet).
An illustration showing how a melting glacier forms and shapes a moraine, a lacustrine plain, a proglacial lake, and other land and water features. This is how the Huron-Erie Lake Plain and Lake Maumee were formed, followed later by the Great Black Swamp.An illustration showing how the shape of the terrain influences a variety of wetlands. The Great Black Swamp's terrain, which was shaped by a glacier, had different kinds of wetlands, upland forests, prairies and savannas.
End moraines are huge, curved ridges of till outline where the outer margin of the glacier once stood. They can hold proglacial lakes and create braided streams and outwash fans. They sometimes exhibit a hummocky land surface across the till plains characterized by rounded knolls and depressions, which are called "knob and kettle topography".[17] One account from the early 19th century noted the glacial alluvium of the lake plain, and described the streams as "sluggish in their motions, their bed having little inclination".[18] The average slope of the land was about 4 feet (1.2 M) per mile.[19] The water saturated a land that had been flattened for tens of thousands of years under the weight of the ice sheet.
Late Pleistocene and Early Holocene animals living around Lake Maumee and the early formations of the Swamp included giant short-faced bears and giant beavers. A fossil remain (a tooth) of the Dire wolf, dated 11,000 to 12,000 years BP, was found east of the former Swamp region in Sheriden Cave, and was later used to study the DNA of the species.[21]
A photo of a replica of Fred the mastodon (Buesching mastodon), pictured left, based on fossils found west of the former Great Black Swamp. Pictured right is a female mastodon fossil.
In 1998, an 80% complete male mastodon fossil skeleton was discovered in Fort Wayne, Indiana, just west of the former Great Black Swamp, and was named "Fred" by the family who found it buried beneath their peat farm.[22] Scientists determined the mastodon's body sank into wetland soils about 13,000 years BP, which helped preserve it because of its low-oxygen environment. They concluded the male mastodon had died from a fatal battle with another male, and that its location of death was likely used by other mastodons for mating grounds.[23] Scientists studied the bones for oxygen and strontium levels to determine how the animal used the landscape.[24] They concluded from chemical signatures in the tusks that the mastodon's diet consisted of conifers such as spruce, which were abundant in the Swamp region during the Late Pleistocene.[25]
Unlike southeast Michigan, the Great Black Swamp in northwest Ohio and northeast Indiana did not have conifer swamps and conifer forests since the early Holocene, thousands of years after the glacial retreat. Research on pollen evidence from the Ohio and Indiana till plains suggests that about 10,300 years BP, the climate warmed from a boreal climate to a temperate climate. This gradually turned the Swamp region from postglacial vegetation and open spruce forest-tundra into a temperate deciduous forest, with deciduous trees completely replacing conifer trees in the till plains by about 9,800 years BP, and with open oak woodlands developing between 8,000 and 4,000 years BP.[26] Climate of the Swamp and the rest of Ohio was impacted by the 8.2 kiloyear event, which was a rapid drop in global cooling temperatures, and included two phases of wind-blown silt, or loess, which was deposited across the region between 8,950 and 8,005 calibrated years BP.[27]
Evidence in northern Ohio of the first Indigenous peoples, known as Paleo-Indians, date to around 11,000 years BP, according to studies of the Paleo Crossing Site and Nobles Pond Site. Evidence from 11,000 to 12,000 years BP of early humans was found at Sheriden Cave, east of the former Great Black Swamp, and included Clovis culture artifacts. A 2012 study suggests humans existed in northern Ohio 13,738 to 13,435 calibrated years BP, based on the discovery of stone-tool cut marks on the bones of a Jefferson's ground sloth, which were found in a bog in the Huron River headwaters, east of the former Swamp.[29]
A 1905 illustration by Jesse Cornplanter when he was 15. The artwork depicts the daily life in a Seneca village centuries ago. The Seneca lived in the Great Black Swamp region, until they and other Indigenous nations were forced to sell the entire Swamp lands to the U.S. government in the Treaty of Fort Meigs in 1817 (Cessions 87 and 88).
As the climate of ancient Ohio shifted to seasons with warmer temperatures, the Indigenous peoples adapted and continued to develop their societies and cultures, from the Archaic period (10,000 years BP) through the Woodland period (3,000 years BP to 1,000 years BP), and through first contact with Europeans, in what became known as Ohio Country, from the mid-17th century and into the centuries after.
The nations in the Great Black Swamp region were part of the Indigenous peoples of the Northeastern Woodlands. Common languages included Algonquian and Iroquoian.[30] The people managed their lands around the Swamp during the wet and dry seasons. Villages would migrate with seasonal changes and when new food sources were needed.[31] Villages depended on hunting and fishing, would grow corn, and cultivate and manage their lands by burning the soil. This is similar to the prescribed burns used today by wildlife and natural resource departments in nature refuges and management areas across the country.
An illustration of Indigenous people harvesting wild rice during the 19th century. These plants existed in the marshes of the Great Black Swamp.A photo of a cedarbark bag for collecting rice made by the Ojibwe (also known as Chippewa), who lived with other Indigenous nations in the Great Black Swamp region.
One archaeological study provides insight not only on the Indigenous, but also on what the Great Black Swamp and its nearby wetlands and their ecosystems used to be like centuries ago. It found the Indigenous harvested wild rice (Zizania palustris), which grew in the freshwater marshes of the Swamp.[32] This plant species is an indicator of healthy, freshwater wetlands, and its sensitivity to environmental conditions can show either a robust biodiverse ecosystem or an unhealthy ecosystem suffering from pollution, problems with water flow, or invasive plants.[33] The plant also supports wildlife, such as deer, rabbits, muskrats, and ducks, with a diet rich in proteins, minerals, and fiber, and also with habitat and shelter.[34] Studies of animal remains inside Indigenous refuse pits, called middens, uncover how the Indigenous hunted for game in the Sandusky Bay section of the Great Black Swamp, including muskrats, ducks, frogs, and turtles, and also fish species such as Freshwater drum, Longnose gar, Yellow bullhead, and Bluegill.[35] Wetland plants such as cattail and bulrush, as well as the inner bark of trees, were also used to make baskets, bags, house coverings, mats, and utensils, and other textile arts.
Archaeologists studied evidence of Indigenous peoples in the Swamp, found buried near the Maumee River in Allen County, Indiana. They analyzed: ceramic pottery; projectile points; stone tools; corn; animal bone; mussel shells; and charcoal from firewood, which originated from beech, ash, hickory, elm, walnut, maple, and white oak.[36] Analysis found the evidence was deposited between 1150 and 1430 AD. A different archaeological site was studied near the Maumee River in Lucas County, Ohio. Scientists analyzed its evidence of a late 18th to early 19th century Ottawa burial, which contained: trade goods; a shelter; an animal enclosure; indigenous and European artifacts such as trade silver; and dietary evidence such as corn, fish, reptiles, and mollusks.[37]
After the reintroduction of horses in the United States, Indigenous peoples used horses to traverse almost any terrain. Another mode of transport were dugout canoes, measuring 15 feet (4.6m) long, which they used to travel across lakes and rivers for miles.[38]
Canoes in a Fog, Lake Superior by Frances Anne Hopkins, 1869. The painting depicts birchbark canoes carrying Indigenous people. Their engineering skills were seen in the canoes' design and wood-frame construction.
Indigenous people built large, sophisticated birchbark canoes that could transport many people and heavy goods. Construction was a process of precise planning, resulting in highly resilient vessels. One 1750s account by frontiersman James Smith described a canoe that was 35 feet (10.7 M) long, 4 feet (1.2 M) wide, and 3 feet (0.9 M) deep.[39]Fur trader records referred to such large vessels as a "6-fathom gunwale length."[40] It was built with birch bark over a light wooden frame, often made of white birch, elm, hickory, chestnut, basswood, and cottonwood from the Swamp. The frame gave the canoe longitudinal strength to achieve high speeds, even when fully loaded. Birch bark was preferred for the boat's skin because it could be easily sewn together with tree roots. Stone axes (made of flint, jasper, and quartz) were used to fell trees. Stone tools were used for woodworking until European metal tools were introduced. Different models were used for specific bodies of water, from calm lakes to fast-moving rivers.[41] According to Smithsonian historians Edwin Adney and Howard Chapelle, the canoes' advanced design and engineering skills showed "a long period of development must have taken place" before European contact.[42]
Birch bark was used to create scrolls, called Wiigwaasabak, for written stories or songs, ceremonial rituals, healing recipes, maps, and artwork by the Anishinaabe and the Ojibwe (also known as the Chippewa). A stylus of bone, wood or other material was the writing stylus, with charcoal rubbed into the etched markings in the bark.[43] Birch bark was also used to make other items, such as boxes called Wiigwaasi-makak, which could store scrolls and other items. The boxes could store food, thanks to the preservative properties of the wood's betulin. The wood's waterproof qualities were useful for protecting food, scrolls, precious items, and also canoes, thanks to suberin, another natural compound in the wood.[44] The Indigenous harvested birch bark without fatally injuring the trees.[45] They respected the life-giving abilities of the Swamp, which was called "Waabashkiki" in the Ojibwe language.[46]
Anishinaabe peoples inhabited the land adjacent to the Swamp for generations.[47] Villages bordered the Swamp, with the Miami people along the Maumee-Wabash portage and along the Great Miami and Little Miami Rivers. The Swamp was the trapping ground for many of the villages in the Ohio River valley, where control was divided by area.[48] It became home to the largest, most prominent settlement of the Shawnee in what would become the state of Ohio.[49] Lower Shawneetown was established in the 1730s.[48]
The Wyandot people lived in villages along the Scioto River east of the swamp, settling as far south as the Ohio River.[48] The Wyandots (also known as the Wyandotte or Wendat) lived at the mouths of the Maumee River and the Sandusky River, inside the borders of the Great Black Swamp. They were treated with equality by the Delaware and the Shawnee and lived in peace together, following their past war-time experiences with the Haudenosaunee (the Iroquois), and in the midst of their new ongoing experiences in the 17th and 18th centuries with the French colonialists and the British colonialists who threatened their autonomy.[50]
Indigenous assimilation, removals, and treaties for the Swamp
Charge of the Dragoons at Fallen Timbers by R.F. Zogbaum, 1895. The illustration depicts the Battle of Fallen Timbers, which took place on the Maumee River in the Great Black Swamp in 1794, and was the final battle of the Northwest Indian War.
The Great Black Swamp's name originated during the War of 1812, possibly referencing its black soil, the way its trees blocked sunlight, or the terrain's challenges for military transport.[54] On September 29, 1812, the first Ohio battle of the war took place in the Swamp between Americans and Indigenous, ending in a draw on the Marblehead Peninsula in Sandusky Bay.[55]Shawnee leaders Tecumseh and Tenskwatawa formed an indigenous alliance to resist American expansion.[56] After their defeat at the Battle of Tippecanoe (1811), this confederacy united with the British during the War of 1812 but disbanded following Tecumseh's death at the Battle of the Thames (1813).
After the Treaty of Greenville (1814) came the Treaty of Fort Meigs in 1817, when the entire Great Black Swamp itself, stretching from Fort Wayne to the shores of Lake Erie, was ceded by the Indigenous peoples to the U.S. government.[57] In 1818, Lewis Cass, Territorial Governor of Michigan, stated an interest to develop northwest Ohio for European-American use, and to take it by force, even if it caused, he said, the "extinction" of the Indigenous peoples living there.[58]
Historians that acknowledge the genocide of the Indigenous peoples, also known as American Indians or Native Americans, often clash with the denials of such human atrocities. An eliminatory dynamic in settler colonialism was driven by the desire to acquire land and resources, and by anti-Indigenous racist beliefs that portrayed the Indigenous as "inferior" and as obstacles to conquest.[59] Although the term Manifest destiny was first used in 1845, the ideas that developed it already existed in places such as northwest Ohio in the early 19th century. The Indian Removal Act of 1830 enabled white settlers to continue the violent and physical removals of Indigenous peoples from their lands.
From 1822 to 1834, the Ebenezer Mission School (or Old Maumee Mission School) operated on the Maumee River in the Great Black Swamp in Wood County. Established by the Western Presbyterian Missionary Society of Pennsylvania, which owned Missionary Island and 372 adjacent acres, it focused on "Christianizing and civilizing the Indians."[61] Rev. Isaac Van Tassel and his wife Lucia ran the complex, which included a two-story Mission House.[62] It had a schoolhouse, a blacksmith shop, a stable, and agricultural land with livestock, and was managed with assistants, teachers, and laborers.[63] The school typically hosted 80 to 150 Indigenous boys and girls, aged 6 to 20. Beyond formal instruction, activities included sports, sledding, making maple sugar, and harvesting thousands of bushels of hickory nuts for sale in eastern markets.[64]
The students were mostly Ottawa, Chippewa, Miami, Shawnee, Munsee, Wyandotte, and Potawatomi. Rev. Van Tassel and the teachers taught Indigenous children at the school, and also taught their parents and elders when they visited them in their lands.[65] They also preached in nearby white settlements.[66] At the School, students learned the Bible, arithmetic, grammar, and geography.[67] Van Tassel and his wife learned Indigenous languages to translate religious lectures and hymns. They gave Indigenous children spelling books, with scriptures and hymns, translated in languages such as Ottawa.[68] The Ottawa children had always called the Western Basin of Lake Erie home, known in their own language as "Gitche Gumegsuwach" (Get-she-gum-eg-sug-wach).[69]
The school had been developing a growing community, until the Indian Removal Act started to induced Indigenous peoples to sell their lands to the U.S. government and moved them out by force. Horrified by the Removals, Van Tassel had the Presbyterian Missionary Society donate 600 to 700 acres of his School's land to the Ottawa people so they could stay.[70] This was not to last. The School closed in April 1834 because of the U.S. government's Indian Removal program, which moved the Indigenous populations west of the Mississippi River.[71] As of 2025, the school is not listed as a boarding school by the Bureau of Indian Affairs.[72]
Additional treaties made during the Removals were the Treaty with the Ottawa in August 1831, which relinquished the lands around what is now the town of Ottawa, Ohio.[73] Another treaty with the Wyandotte in 1832 relinquished the lands north of what is now Carey, Ohio, and which now include the Springville Marsh State Nature Preserve.[74] A final treaty, this time with the Ottawa, signed in February 1833, would relinquish the lands on the shore of the Maumee River opposite the future city of Toledo.[75]
In 1841, by the Portage River in the Great Black Swamp, a group of white people murdered a Wyandot, Chief Summundewat, who was one of the most vocal leaders opposed to the Indian Removals.[76] On March 17, 1842, the Wyandot Tribal Council signed a treaty with Special Commissioner John Johnston and sold all of their remaining lands in Michigan and 109,144 acres in the Ohio counties of Wyandot and Crawford.[77] In 1842, Charles Dickens, who was traveling through the U.S. at that time, met with the last of the Wyandot people in Ohio, and with Johnston himself, who had just negotiated the treaty. Dickens wrote about this encounter in his book, American Notes. He observed some of the Wyandot arguing with each other over the Removals, and he listened to Johnston, who spoke to him about the Wyandot, and gave him "a moving account of their strong attachment to the familiar scenes of their infancy, and in particular to the burial-places of their kindred; and of their great reluctance to leave them".[78]
By 1843, the Indian removals in Ohio completed the process of white settlers stripping the land away from the many Indigenous peoples whose ancestors had called northwest Ohio and the Great Black Swamp home for thousands of years, including the Wyandotte, Seneca, Delaware, Shawnee, Potawatomi, Ottawa, Chippewa, Miami, Eel River, Wea, Kickapoo, Piankeshaw, and Kaskaskia. Other Indigenous peoples affected by the Removals included the Peoria and the Munsee, who, while not permanent residents of northwestern Ohio like the other nations, did have a significant presence in the area.
During the Removals, Americans authorized to work with the Indigenous as agents assured them they would always own the land they would be moved to out west, in Indian Territory. Records indicate an agent was told by a Wyandotte chief:
He promised the same thing to us at our last treaty; that if we would sell all but this reservation, he would protect us from the encroachments of the whites, and keep us in peace, and never ask us to sell another foot of our land. This was not ten years ago; and now you are at your old trade of trying to drive us away again. Besides, it would be no better if we were yonder; for there is no land or swamp so poor, but white men will want it; and if the President did not fulfill his word here, will he do it yonder? No! You white men never will be satisfied till the blue water of the great lakes, in which the sun sets, has drank the last drop of Indian blood. Here are our homes; and we are now beginning to live comfortably… Here, too, are the graves and bones of our fathers, our wives, and our children.[79]
After the defeat and forced relocation of the Indigenous population, drainage of the Great Black Swamp increased in parallel with the settlement of white Americans into the area.[47] Although dry upland areas around the Swamp were settled in the early 19th century, the wet, muddy wetland terrain itself delayed development by several decades. The Black Swamp Mutiny occurred in 1813 during the Battle of the Thames, when American soldiers got lost while marching to fight the British in Ontario, causing their prisoners to revolt without bloodshed.[80] The Swamp's impassibility was a problem during the Toledo War (1835–36). The Michigan and Ohio militias were unable to traverse the area and never engaged. Although a corduroy road was built in 1825 and graveled by 1838, travel could still take weeks. Wheeled transportation was impossible most of the year, and local residents thought the rigors of travel to be unsuitable for anyone except adult men.[81]Malaria inhibited settlement until the region was finally drained, drying up the mosquito-breeding grounds.
According to a Michigan Natural Features Inventory report on the 1816-1856 GLO surveys, "Surveyors were instructed to note the exact location of wetlands, lakes and streams, comment on the agricultural potential of soils, note the quantity and quality of timber resources… Tree species and diameter was also noted… Recently burned areas, windthrows, and beaver floodings were recorded along the section lines, as were various cultural features, of either Native American or early-European settler origin."[82] These records created to sell land to 19th-century settlers are now being used today to create Geographic Information System (GIS) presettlement vegetation maps for Ohio.[83] Researchers can use these maps to identify environments that existed over 200 years ago. These maps record in great detail the Swamp's extent in Michigan.[84] They also record the Swamp's extent in Indiana.[85]
GIS presettlement vegetation maps show the Great Black Swamp was not uniform, but a composition of varied wetland fragments shaped by elevation and terrain. The outline was defined by three main continuous wetland areas:
Depending how certain areas are measured on maps, the Swamp's size can range from about 1.5 million acres (607,028 ha) to the estimate of over 3 million acres (1,214,057 ha) from the Ohio Department of Natural Resources.[5] Outliers potentially missed by surveyors measuring wetlands in the early 19th century was how seasonal precipitation expanded the Swamp's borders, turning dry forests into flooded forests, dry prairies into wet prairies, and other dry areas into vernal pools.
Border Settlers in Ohio by F.O.C. Darley, 1876. The print shows how settlers had to be inventive and resilient to survive. They felled trees and drained wetlands to farm.An image from Land Draining; a Handbook for Farmers on the Principles and Practice of Farm Draining by Manly Miles, 1892. It shows tiles laid 3 to 4 feet deep, visible beneath the person's foot, which lowered the water table and drained excess water into man-made ditches, allowing farmers to grow crops.
GIS presettlement vegetation maps can also verify claims about the Swamp, such as one about Charles Dickens' 1842 Columbus to Upper Sandusky stagecoach trip as having been inside the Swamp.[86] GIS maps show this route was not in the Swamp.[83] That trip included a corduroy road that produced, Dickens wrote, "the very slightest of jolts" that could "have dislocated all the bones in the human body."[87] Dickens later left Upper Sandusky by stagecoach for Tiffin, where only then did he travel through the actual Swamp by train to visit Sandusky.[88]
The Land Act of 1820 had brought the minimum price of land in the U.S. down from $2.00 per acre to $1.25 per acre. This price drop helped stimulate interest in areas like the Swamp. Settlers bought parcels of land in the Swamp within the Congress Lands, which were for sale to the general public, and established themselves within the survey townships.
Settlers, such as individuals and families, were able to buy land under the Preemption Act of 1841 and the Homestead Acts. Vagueness in the laws enabled rich investors and land speculators to buy large tracts of land sight unseen, and engage in fraud.[89]
In the 1850s, the states began an organized attempt to drain the swamp for agricultural use and ease of travel. Various projects were undertaken over a 40-year period. The Swamp Land Act of 1850 advanced the drainage of wetlands across the United States, including the Great Black Swamp. In 1859, the Ohio General Assembly passed the "Ohio Ditch Law", enabling settlers to build ditches that would turn wetlands into farms.[90]
Settlers drained the Swamp from the 1850s to the mid-1880s. They hand-dug ditches to lower the water table, then buried clay tiles (pipes made from local clay) in the exposed ground to drain excess water into the ditches. Settlers farmed the land's soils, which historian Henry Howe described as a foot of "black decaying matter" over several feet of "rich yellow clay", followed by a "stratum of black clay of great depth."[91]
Settlers built their homes on the river banks and sand ridges.[92] They often made their homes out of logs, and hunted game in the Swamp for food, and for skins and furs to make clothing and other items.[93] Settlers caught large quantities of fish in the Sandusky and Maumee Rivers.[94] In open wet prairies without trees, water could be 4 feet (1.2 M) deep, going up to a horse's saddle skirt.[95] Martin Kaatz, a historian from the mid-20th century, wrote about accounts from the early 19th century that stated the trees were 100 feet (30 M) high, and that their leaves "nearly shut out the sun's rays except during the period of high sun".[96] Howe also described the Swamp's dense forests and foliage as being "almost impenetrable to the rays of the sun", making the Swamp daunting for white settlers.[91]
"Confused speculation": Public health crises in the Swamp
Diseases and epidemics were common during the draining of the Swamp. An Ohio public health official in the 1940s commented on the general ignorance in Ohio about diseases and epidemics between 1788 and 1873, describing it as "confused speculation".[97] Symptoms were recorded in medical journals and notes during that time. The causes of many diseases were not known, and their high mortality rate possessed the first settlers in the Swamp with fear and panic. Settlers often blamed the Swamp itself for every death, infection, and injury, leading many to call the City of Toledo and the Great Black Swamp, "The Graveyard of the Midwest".[98] One incident in particular involved the town of Gilboa in 1852, which was located next to the Swamp in Putnam County. A cholera outbreak caused nearly 600 people to flee the town in fear and terror, and 13 people were reported killed by the cholera.[99] It was later determined that a damp cellar that stored trash and decomposing vegetable matter was the source of the outbreak.[100]
Dr. Daniel Drake was one of Ohio's prominent physicians who encouraged education as the first line of defense against epidemics by working with local governments in Ohio, and by publishing books and pamphlets on infectious diseases with the best information available at the time.[97] In 1850, Drake published a book connecting geography to disease, in which he blamed the Great Black Swamp for what he described as "autumnal fevers" that afflicted and even killed large numbers of people.[101]
However, while wetlands and even migrating waterfowl are contamination vectors for diseases like cholera, caused by the bacteria Vibrio cholerae, and also Pasteurella multocida, or avian cholera, it is ultimately the lack of human hygiene and sanitation that lead to cholera epidemics.
The Ghost of the Swamp by Maurice Sand (or Maurice Dudevant), 1850. The illustration is an allegory of malaria. Its mortality and infection rates in the Great Black Swamp are unknown, due to ignorance and unreliable medical information and treatment in the mid-19th century.
Malaria was deadly in the Swamp, yet settlers were unaware that mosquitoes, not "bad air", transmitted it until Charles Louis Alphonse Laveran's discovery of Plasmodium in 1880. A 2008 study of U.S. malaria from 1850–1860 highlighted widespread public health ignorance at that time, noting how settlers didn't know building ditches could create mosquito vectors, that mosquitoes favored rainfalls, and that temperature was the most crucial risk factor for infections.[102] "Confused speculation" led to common misdiagnosis, leaving the exact number of malaria deaths in the Swamp unknown. Even the 1870 U.S. census noted the lack of sufficient death records as the "gross incompleteness of the Returns of Deaths". The census mapped a high proportion of malaria deaths in northwest Ohio.[103]
Indigenous peoples around the Swamp suffered significant population losses from the 17th to the 19th centuries due to disease endemics. Ironically, these major outbreaks did not originate in the Swamp, but from European and early American settlers who brought new viruses to which they were already immune. These introduced diseases, such as smallpox in the mid-17th century, decimated Indigenous communities across North America.[104] Diseases killed an estimated 90% of all Indigenous peoples across the Western Hemisphere.[105] Indigenous peoples had lived with the Swamp for at least 13,000 years, but populations significantly declined only after contact with Europeans diseases. Germ warfare used by European-Americans to gain military and territorial advantage over the Indigenous was also a problem.[106]
By the 1860s and 1870s, germ theory became more widely accepted as the cause for diseases, thanks to prominent advocates in the late 19th century. Public health was significantly improved in 1886, when Ohio's government created a State Board of Health to educate the public, to help prevent the spread of infections and diseases, and to end the era of "confused speculation".[107]
The Underground Railroad in the Great Black Swamp
A photo of Reverend William King (1812–1895), minister and abolitionist. Rev. King established a settlement in Canada for American runaway slaves. The trail to Canada would lead them through the Great Black Swamp. An estimated 1,000 people followed this trail to the Elgin settlement in Buxton.An 1863 illustration of a runaway slave hiding in a swamp from slave catchers and their dogs. Wetlands like the Great Black Swamp helped slaves in the Underground Railroad.
The Great Black Swamp offered hope for people escaping slavery from the American South in the form of the Underground Railroad. During slavery, wetlands played critical roles in concealing the movement of slaves escaping southern plantations to the North. The Great Dismal Swamp in North Carolina and Virginia, for example, shielded everyone, including the people who lived there and the people traveling to the next station towards safety in the North.[108]Harriet Tubman worked as a slave her whole life in the marshes and swamps of the Eastern Shore of Maryland, which gave her the skills to help navigate the difficult wetland terrain to gain her freedom, and to lead others out of slavery.[109] In the midwest, The Great Black Swamp was joined in the Underground Railroad by wetlands in Indiana, such as the swamps and marshes of Marion County where mostly Quakers, devoted to the abolitionist movement, led the slaves to freedom.[110] People who helped the slaves in the Underground Railroad were called agents and operators. They took massive risks by violating the Fugitive Slave Act of 1850, which demanded the return of slaves to their owners.
Ohio never had slavery, but it was settled by many white people from the South who continued other forms of oppression and discrimination by creating the Black Laws of 1804 and 1807. By codifying white supremacy in Ohio, black people lived there under the strictest and cruelest restrictions, and they were even exposed to being kidnapped and trafficked to the South where they would be sold to enslavers.[111] This made the Great Black Swamp even more important for the Underground Railroad as its often difficult terrain and foreboding presence to the locals helped to conceal slaves fleeing to Canada.
In 1998, the U.S. Congress passed legislation to create a National Park Service program called the Network to Freedom, in order to honor, preserve, and promote the people who helped free the slaves.[112] The Network to Freedom officially recognizes three sites used for the Railroad that were in the Great Black Swamp, and provides a map of their locations.[113] This map can be cross-referenced with GIS presettlement vegetation maps to understand what the slaves saw in the Great Black Swamp.[83]
One site is the Howard Family Farm on Beaver Creek in Grand Rapids in Wood County, which existed in an area (according to early land surveys) that consisted of mixed oak forests, beech forests and elm-ashswamp forests south of the Maumee River. The John King Farm is a second site across the Maumee River, and served as a station for the Railroad from 1838 until the end of the American Civil War. It was located at Route 109 in Delta, Fulton County, in an area that consisted of oak savannas and elm-ash swamp forests. Connected to stations near the Michigan border, this site was also followed by the King Cemetery, the third site, located further north in Delta, Fulton County, in an area that was all elm-ash swamp forests.
The Cemetery memorializes the abolitionistReverend William King, founder of the Elgin Settlement (North Buxton) where many people escaping slavery sought freedom. Rev. King began his mission to free the slaves in 1848.[114] His story was told in Annie Straith Jamieson's 1925 book, William King: Friend and Champion of Slaves.[115]
An 1861 illustration depicting runaway slaves hiding in a marsh. Before slaves reached the Great Black Swamp to escape to Canada, they already had experience using wetlands in the slave states to evade capture.
Rev. King's brother, John King, who lived in Findlay and was known locally as "Uncle John King", was one of many people who initiated escapes and hid slaves in barns, cellars, pens, garrets, cornfields, sacks, and other hiding places within the Swamp's counties of Wood and Hancock. Historians estimate 1,543 to over 2,000 Underground Railroad agents and operators in Ohio helped between 40,000 and 50,000 fugitive slaves escape to ports near Cleveland, and escape through the Great Black Swamp to ports near Toledo and Sandusky to cross Lake Erie and find freedom in Canada.[116]
Runaway slaves used every effort to baffle their slave catchers trying to recapture them for their owners in the slave states. Slaves could use the Great Black Swamp's terrain to their advantage, which was already known to the locals and even the military as "impassable", with its "knee-deep" muck and thick growth of beech trees.[117] Historians believe more stations existed in the Underground Railroad between the Ohio River and Lake Erie than the official records state because of the massive organization of effort and resources to deliver slaves to freedom.[116] The Swamp played an important role in that endeavor.
New arrivals: Farming and industry
A late-19th-century photo shows a work crew clearing the Great Black Swamp for a railroad extension. The resulting rail lines, like the Baltimore and Ohio Railroad, were built through the former Swamp region to transport lumber and crops by steam train.
After the American Civil War, the United States focused on westward expansion, and by the 1860s, more than 30,000 miles of railroad track existed in the nation. The railroads of Ohio consumed 1 million cords of wood annually just for fuel (the amount of wood used for railroad ties is unknown), leading to intense timber cutting and land clearing which eliminated most of Ohio's wetlands, including the Great Black Swamp.[118]
Arriving alone or with their families, settlers felled trees, built their homes and furniture, dug ditches, hunted wild game for food, and prepared their land for their crops and dairy. Other enterprises emerged to expand the wealth of the settlers, including gristmills and sawmills, logging and lumbering, and then later, in the 1880s, oil and gas fields in Wood and Hancock counties.[119] High pressure natural gas was discovered near Findlay while drilling for water in 1884, and petroleum was first discovered in Lima in 1885.[120] Findlay and Bowling Green were the two principal centers of fossil fuel production in the 1880s, creating a manufacturing industry that included glass factories and lime burning.[121]Iron ore imported to Ohio was smelted in Paulding County from the late 1860s to the mid-1880s, with each furnace burning charcoal from about 1,000 acres of local forest each year.[122] More than 50 drainage tile factories operated in northwest Ohio by 1880, in compliance with Ohio's Ditch Law and with the land draining needs of the farmers, factories, and land owners.[123]
As white settlers from other parts of America arrived in northwest Ohio to turn the Swamp into farmland, so too did an influx of immigrants from Europe. Irish immigrants helped to drain the swamp, build churches, and develop the land while also bringing their culture and customs to the area.[124] German-speaking people, from the Austrian Empire, Switzerland (which was coming out of the Napoleonic era), the German Confederation and then later the German Empire, and other regions from Central and Eastern Europe, also contributed to the transformation of the Swamp into agriculture.[125]
Immigrants helped build the Miami and Erie Canal from 1825 to 1845, which ran down the middle of the Swamp from Toledo to Defiance along the Maumee River, and south through Paulding and Van Wert counties. The canal provided a supply route for farm products, logging, and other commercial goods.
A large wave of Polish immigrants arrived in Toledo and northwestern Ohio in the 1870s and 1880s, when much of the Swamp was already drained. Other ethnic groups fleeing economic, religious, and political challenges from Central and Eastern Europe included people from Galicia, in what is now southeastern Poland and Western Ukraine. While some of these immigrants worked in the various industries in Toledo, others farmed in the former Great Black Swamp, with the ability to own their own land, a right that had been taken away from them back in their homeland.[127]
The Swamp's rich, geologic soils provided a new beginning for African-Americans in farming. This was not made easy by the Ohio Black Laws of 1804 and 1807, which made black people pay a residency fee, register with the county clerk, have a white Ohian as a sponsor, and obtain travel and freedom papers, all under the threat of expulsion.[128] African-Americans who achieved success included Archibald Worthington, a former slave who moved from Virginia to northwest Ohio. In 1855, near his 160-acre farm in Defiance County, he created a cemetery which he platted for and donated to other African-Americans.[129] His cemetery and farm were south of the Maumee River in what used to be elm-ashswamp forests, prairie grasslands, fens, freshwater marshes, and beech forests, according to GIS presettlement vegetation maps.[83] The cemetery received a historic marker in 2025.[130]
A 2009 study described African-American lives in northwest Ohio during the early to mid-19th century, including: one colony that lived on 750 acres in Van Wert County; how the family of Godfrey Brown, a runaway slave and Continental Army soldier, brought relatives to Van Wert after buying their release from a Southern plantation in 1830; and generational land owners in Paulding County, like Charles Williams, born 1867, who lived and worked on the farm his grandfather had bought after fleeing slavery.[131] The study claimed racial prejudice was rare where black people lived in Paulding, Van Wert, and other counties in the Great Black Swamp, and that black residents sometimes married white and Indigenous people. A 2024 report claimed race riots in the 1870s pushed out many black families from the region.[132] This contributed to black land loss in the United States.
Industrialists capitalized on the Swamp's rich natural resources, including Eber Brock Ward. In 1863, he purchased 4,089 acres of swamp and marshes along Lake Erie in Lucas County and called it "New Jerusalem" (which later became Jerusalem Township). He had a canal dug between Cedar Creek and Lake Erie to transport goods. He brought a steam-powered dredger to help dig the canal, but most of the work was done by hand. Lumbering was profitable until 1895, when a muck fire burned for three months, destroying the rest of the trees near the canal.[133]
Bowling Green resident James B. Hill expedited the draining of swamps with his Buckeye Traction Ditcher.[134] Hill's ditching machine laid drainage tiles at a record pace. First built in 1893, it was the first successful steam-driven tractor ditcher.[135]
The construction of an extensive ditch network facilitated the conversion of wetlands into farmland. Railroads and drainage tile industries also contributed to the Swamp's destruction.[136] The Jackson Cut-Off Ditch helped destroy the Wood County Swamp. Built at a cost of $110,000 in the mid-19th century, it drained 30,000 acres (12,140 ha) by intercepting the meanders of Yellow and Brush Creeks and the North Branch of the Portage River.[137] This ditch diverted those headwaters into Beaver Creek and the Maumee River to drain parts of Wood, Henry, Hancock, and Putnam counties.[138]
Lidar-based digital elevation models (DEM) reveal the deep vertical and horizontal ditches dividing the land and routing water toward the Maumee River. These images contrast the ditches with the shallow, meandering channels of the creeks and streams that existed prior to settlement. Today, farming communities must constantly maintain these ditches to prevent local and upstream flooding.
The 1920 United States census reported that the State of Ohio had a total of 24,984 miles of completed open ditches and 9,205 miles of completed tile drains (both numbers excluding ditches and tile drains that were being planned or under construction).[139] About 15,000 miles of these reported ditches were in the former Great Black Swamp region alone.[140]
Ohio had over 24 million acres of forest, but by 1883, it only had 4 million.[141] By the late 1880s, virtually all of the trees in the Swamp were cut down and used for fuel and lumber. It took years to remove the tree stumps and build the ditches before the land could be farmed. The last photograph of the Swamp, taken in Paulding County in 1890, shows a field covered in tree stumps with small pools of water, stretching as far as the eye can see.[142]
Historian Martin Kaatz romanticized the way settlers engaged with nature, stating they had to "wage war" with the environment, and "trees had to be felled, underbrush cleared, stumps removed, and predatory animals killed".[143] Between 1800 and 1855, settlers had completely extirpatedwolves, bobcats, elk, mountain lions, and bison from Ohio, and by 1881, the last black bear was killed in Paulding County, in the heart of the former Great Black Swamp, where settlers were almost finished with clearing the trees and draining the wetlands for farming.[144] The Passenger pigeon also inhabited the Swamp, living among the trees unbothered by the muddy surface, but it was hunted to extinction, with the last one dying in Ohio in 1914.[145]
In the 19th century, most people favored draining and farming wetlands. Even Charles Dickens noted in 1842 that a wetland he observed near Cincinnati had not been "reclaimed".[146] However, this period also saw a growing recognition of human and environmental abuses. In Hard Times, Dickens, who was anti-slavery, opposed the way industrialists applied utilitarianism to minimize and exploit workers as "objects" for maximum economic "utility".[147] Other problems in the 19th century like utilitarianism were extractivism, which also treated people and environments only as commodities for maximum "utility", causing environmental destruction and human rights abuses. Manifest Destiny proclaimed that if indigenous lands were not cultivated, they were being "wasted", which was a fallacy white Americans used to seize, settle, and farm indigenous lands.[148] With these mindsets, wetlands were perceived as "wastelands" meant to be converted into "productive property" for maximum commercial profit.[149] The harms caused by the excessive exploitation of the environment would take time to be recognized and understood, and eventually led to the first scientific and government management of natural resources and wildlife in the country.
Natural resource management did not exist at all in the 19th century until rapid deforestation and industrialization in the U.S. made people in the late 19th century more aware of the dangers of exploiting the land and overexploiting forests and wildlife. The Ohio Fish Commission (established 1873) and the Ohio Forestry Bureau (established 1885) were among the first government agencies to manage Ohio's natural resources.[150] But for the Great Black Swamp, they were too late.
Over the course of less than thirty years (1859–1885), the Great Black Swamp, once teeming with countless plants and animals, was almost completely erased from the land that had slowly shaped it since the end of the Younger Dryas period about 11,700 years ago. As of 2024[update], 80% of the Great Black Swamp area has been planted with corn, soybeans, and wheat; only 0.02% of the Great Black Swamp remain as freshwater wetlands.[4]
Economic and population growth
The Great Black Swamp's unique soils powered agricultural growth in northwest Ohio. This growth can be studied from 19th and 20th century state and federal census records, despite their incompleteness. A fire in 1921 destroyed many of the U.S. census archives from 1890.[151] Thankfully, population statistics can be found with the State of Ohio in their 1920 census, which records information from every decade between 1850 and 1920.[152]
The total population for the 13 Ohio counties within the former Great Black Swamp in 1920 was 675,761. It was 207,922 in 1860, when settlers had spent a year beginning to turn the Swamp into farms since the Ohio Ditch Law was passed in 1859.[152]
In 2022, the United States Department of Agriculture (USDA) Ohio census reported on the number of farms and the actual revenues from Allen, Defiance, Fulton, Hancock, Henry, Lucas, Ottawa, Paulding, Putnam, Sandusky, Seneca, Van Wert, and Wood counties in the former Swamp. In total, the 13 counties reported there were 11,348 farms, and the counties generated $2,144,563,000 in revenues from crops, excluding products from livestock and poultry. The majority of the crops were soybean, corn, and wheat.[154] In 2020, the total population of the 13 Ohio counties was 1,085,831.[155]
The Swamp also continuously stretched without interruption into Allen County in Indiana. In 1920, the census reported there were 4,221 farms in Allen County, and the reported total "Value of All Crops" from those farms, excluding products from animals, was $11,054,888 (not adjusted to current rates).[156] In 2022, the USDA census reported there were 1,497 farms and $254,903,000 in crops sold, excluding products from livestock and poultry.[157] In 1920, the total population for Allen County in Indiana was 114,303.[158] In 2020, it was 385,410.[159]
The Swamp north of the Maumee River continuously extended into Lenawee and Monroe counties in Michigan. Like Ohio and Indiana, Michigan also drained and developed the Swamp's wetlands for farming. According to the 1920 census, both counties had a total of 9,188 farms, and the reported total "Value of All Crops" from those farms, excluding products from animals, was $21,878,825 (not adjusted to current rates).[160] In 2022, the USDA census reported both counties had 2,327 farms and earned $435,654,000 in crops sold, excluding products from livestock and poultry.[161] The 1920 census stated the total population for both counties was 84,882.[162] In 2020, the population for both counties was 254,232.[163]
In 2022, the counties inside the former Great Black Swamp (13 in Ohio, 2 in Michigan, 1 in Indiana) earned a combined total of about $2.8 billion in crop revenues (excluding cattle and livestock products) for the agricultural economies of their states.
Public perception about wetlands and the environment has changed significantly in the 2020s, with increasing scrutiny for bias, stereotypes, and the glaring omissions of historical accounts. Public misinformation and misunderstandings about the Great Black Swamp include a 1982 WBGU-TVPBS documentary, which omitted many facts, portrayed the Swamp as a disease-infested place that needed to be destroyed, and described its destruction as a "heroic conquest".[164]
In March 2024, the United States Fish and Wildlife Service (USFWS) issued a press release warning the public about how the loss rates for U.S. wetlands has increased by 50% since 2009, and that wetland conservation is needed, stating, "wetland loss leads to the reduced health, safety and prosperity of all Americans".[165] In April 2025, PBS Western Reserve released a short documentary about the Great Black Swamp and the importance of wetlands, stating, "the misunderstanding of what wetlands provide to nature poses the threat of continued loss."[166]
A photo of an Ohiowetland, restored in collaboration with a private landowner.An illustration showing how a wetland filters and transforms nutrients, such as nitrogen and phosphorus, in the water. Aquatic plants, hydric soils, bacteria, and microbes work together in the denitrification of the water.
Wetland conservation in the United States is supported by a variety of government agencies, communities, farmers, and non-profit groups devoted to protecting existing wetlands and restoring those that are lost or degraded. Historically, efforts were undertaken in the latter half of the 20th century to restore portions of the swamp to its pre-settlement state (e.g., Limberlost Swamp).[168] Following the recurrence of excessive harmful algal blooms in western Lake Erie since 2011, there's been renewed interest in restoring wetlands in the drained Black Swamp area.[123]William J. Mitsch called for the restoration of 150 sq mi (400 km2) of the original Great Black Swamp.[169] This would significantly reduce phosphorus inflow by 40% from the polluted Maumee River to Lake Erie.[4]
The Olentangy River Wetland Research Park is a 52-acre facility dedicated to wetland science, research, and education, while also advising on water resource management, conservation, and restoration projects. The park’s infrastructure supports this mission, featuring two experimental wetland basins, an oxbow wetland, bottomland hardwood forest, a mesocosm compound, laboratories, a classroom, offices, and meeting spaces. Its work contributes specifically to research on restoring water quality and wetlands within the Maumee watershed.
The Black Swamp Conservancy, founded in 1993, has also been involved in preserving former swamplands. They currently protect 17,600 acres (7,100ha) spread throughout the Northwest Ohio region.[170] Their recent work includes the Clary Boulee McDonald Preserve, which became the Seneca County Park in 2024. The site sits next to Wolf Creek on what used to be Beech Forests surrounded by Elm-Ash Swamp Forests back in the mid-19th century. The restoration work to its floodplain and wetlands would create opportunities for wildlife corridors, and also for visitors who would use its trails.[171] The organization works with the community of local farmers that surround any restoration area, in order to have positive impacts on its neighbors.[172]
The Oak Openings Region hosts several protected areas, including preserves managed by The Nature Conservancy and the Ohio Department of Natural Resources (Ohio DNR). The Nature Conservancy owns the Kitty Todd Nature Preserve (about 1,400 acres in Lucas County), an assemblage of oak savanna and restored wetlands. Early settlers avoided farming this area due to its sandy soil.[173] Historically, the region consisted of unique, varied vegetation, ranging from wet sedge meadow to wet prairie to oak savanna, sustained by wind-blown sand dunes and wetlands that cycled from wet (winter/spring) to dry (summer).[174] The Ohio DNR manages sites like the Campbell State Nature Preserve and the Irwin Prairie State Nature Preserve (207 acres of wet sedge meadow), both in Lucas County.[175]
Metroparks Toledo is another regional leader in wetland restoration, most notably through the creation of Howard Marsh Metropark. This restored wetland converted nearly 1,000 acres (400ha) of historical agricultural land into a prosperous wetland that now boasts over half of the bird species found throughout Ohio.[176]Pearson Metropark is another example of both a historic, old growth wet forest, paired with sections of restored wetlands.[177]
In 2024, the U.S. Army Corps of Engineers (USACE) completed a 5-year restoration of 12 acres of coastal wetlands at Port Clinton in Ottawa County. According to the land surveys from the early 19th century, the area the USACE restored used to be freshwater fens and marshes, and also elm-ash swamp forests. Upon project completion, the USACE stated, "Wetlands are essential to the health of our Great Lakes".[178]
In 2014, toxic cyanobacteria impacted the water quality so severely that the water supply for the city of Toledo was shut off, affecting its residents.[4] The destruction of the Great Black Swamp, that filtered runoff before it entered the lake, contributed to the harmful algae blooms and the eutrophication of Lake Erie.[179] Over $10 million were estimated in lost shoreline property value services, and more than 500,000 Toledo residents could not drink the city's tap water for 3 days.[180]
Harmful algal blooms (HAB) are a threat not just to economies and ecosystems, but also to the safety of public health. Airborne HAB toxins can cause eye irritation, breathing problems, and trigger asthma attacks.[181] HABs can harm human beings when cyanobacteria release powerful toxins such as microcystin and microcystin-LR, which can harm the human liver, worsen pre-existing colitis, exacerbate lung inflammation in asthma, and amplify the non-alcoholic fatty liver disease which is common in people living with diabetes.[182]
Algal blooms can hurt Ohio's economy. A 2017 study determined Ohio lakeshore homes can lose 22% of their value when located near algal-infested waters.[183] A 2018 study determined algal blooms that cause the closure of the Western Basin of Lake Erie could cost Ohio beach and fishing recreation $59.2 million and $5.3 million each year.[184] The International Joint Commission estimated Ohio lost $71 (U.S.) million in economic benefits from the 2011 algal bloom event, and lost an additional $65 million from the 2014 algal bloom event.[185]
In 2019, Gov. Mike DeWine established H2Ohio, a statewide water quality initiative to help control and prevent algal blooms in Lake Erie by working with farmers to reduce nutrient pollution and improve the health of waterways. The program supports projects such as two-stage ditches, which help filter the water from nutrient pollution by expanding existing ditches to create vegetation benches that absorb nutrients from farm runoff, slow water flow, provide bank stabilization, reduce maintenance costs, and help prevent algal blooms in Lake Erie.[186] In 2023, the Ohio Department of Agriculture awarded $4.2 million in grants for twelve two-stage ditch projects.[187] Vegetation benches are built below the outlets of the tile drains that remove water from the farms. H2Ohio also supports and funds wetland restoration.[188] In 2025, the Ohio House and Senate proposed more than $120 million in cuts to H2Ohio over the course of two years, which would reduce H2Ohio's budget by 45% and potentially undo years of important progress in improving water quality.[189] Gov. DeWine signed the House Budget bill with the proposed cuts in July 2025.[190]
An Ohio EPA map showing Total Phosphorus (TP) loads from Lake Erie watersheds (2009–2019). It measures the total phosphorus by Metric Tons Annually (MTA).
In 2022, the Ohio EPA published a report, based on years of water quality research and analysis. It stated the Maumee watershed contributes the most phosphorus pollution to Lake Erie.[191] The Great Black Swamp consisted of the Maumee River watershed, and also the Ottawa River, Cedar-Toussaint Complex, Portage River, and Sandusky River watersheds. Combined, all five watersheds produce most of the nutrient pollution in the Western Basin of Lake Erie. Row crop production of corn, soy, and wheat uses fertilizers with phosphorus, nitrogen, and potassium in the farm soil from both commercial sources (such as chemically refined minerals such as superphosphate, monoammonium phosphate, and diammonium phosphate) and organic sources (such as manure, composts, and biosolids). Nutrient pollution from cattle and animal hog units and concentrated animal feeding operations (CAFOs), legacy phosphorus, and non-agricultural stormwater are also recognized in the report as pollution sources. The report aimed to help develop strategies to identify where to best apply nutrient pollution controls in a cost-effective manner.
Reduced gains from phosphorus management can compound efforts to improve and restore water quality in the Maumee River watershed (the former Great Black Swamp). Conservation tillage practices, such as no-till and ridge-till, aim to minimize soil disturbance, improve soil health and reduce erosion by covering 30% of the soil with crop residues after planting.[192] However, such practices may increase the dissolved phosphorus in the farm runoff entering ditches and streams, which can worsen when manure is applied to the soil.[193] These new phosphorus sources combine with "legacy phosphorus" (older phosphorus deposits stored in the banks of ditches and streams from previous years), and complicate restoration efforts unless new methods of controlling stream bank erosion are practiced.[194] The growth of swine production and CAFOs in the former Swamp region greatly contribute to nutrient pollution and require serious manure and fertilizer management.[195]
Destroying the Swamp and all of its nutrient-absorbing vegetation (trees, shrubs, aquatic plants), and replacing it with intensive farming of monoculture (corn, wheat, soy) did not just shut down the environment's ability to control nutrients in the water. It also created brand new sources of nutrients for which the current degraded environmentimpacted by farming simply cannot cope with.
The U.S. Department of Agriculture (USDA) and the Natural Resources Conservation Service (NRCS) assist farmers in preventing nutrient pollution by restoring wetlands on farms through voluntary programs.[196] Other voluntary nutrient pollution control programs include denitrifying bioreactors and drainage water management, also known as controlled tile drainage.[197] Controlled tile drainage manages the drainage volume and water table elevation by regulating the flow from a surface or subsurface farm draining system.[198] Without interference from harmful environmental land uses, this drainage method can significantly reduce growing season fluxes of stream water ammonium nitrogen, nitrate nitrogen, dissolved reactive phosphorus, and phosphorus.[199]
A photo of an Edge-of-Field Monitoring equipment installed at the edge of an agricultural field to analyze and measure nutrient pollution before it enters local waterways. Northwest Ohio farmers in the Maumee Riverwatershed (the former Great Black Swamp) are voluntarily using a network of this equipment.
The USDA and NRCS utilize a voluntary Edge-of-Field Monitoring network across northwest Ohio's 4.5 million-acre Maumee River watershed to measure and manage phosphorus runoff.[200] Installed at field edges, the equipment analyzes water from tile drains and surface runoff to quantify nutrient loss.[201] This helps farmers optimize fertilizer timing and placement.[202] This data allows participating farmers to make better-informed decisions that maximize yields and conserve resources.[203] The network also provides essential validation data for scientists to refine numerical models, ensuring conservation practices protect future water quality and farmland.[204]
The Ohio Department of Natural Resources (Ohio DNR), the USDA, and the NRCS assist farmers with windbreaks and other soil conservation methods to prevent wind erosion, which in turn improves stream water quality.[205] Both government agencies and farming communities work to mitigate the loss of productive soil, recognizing each lost ton as a financial loss for farms and a significant loss of essential nutrients. Optimal soil contains 2 pounds of nitrogen, 9 pounds of phosphorus, and 31 pounds of potassium per ton.[206]
A 2013 study analyzed the perspectives of farmers in the Maumee River watershed concerning phosphorus control and algal blooms in Lake Erie. It noted how nutrient pollution control in Ohio is voluntary (not mandatory) for farmers. The study analyzed many perspectives from the farmers, including how they perceive nutrient control measures, the financial and personal risks they take in running a farm, and how they often have to prioritize "economic over environmental risk".[210]
Personal risks in farming require greater public attention, including threats to both physical health and mental health (such as farmer's lung and suicide), and other risks that can lead to severe injury or death.
In June 2025, the United States Environmental Protection Agency (EPA) selected the Ohio Department of Agriculture for a $1 million grant to provide technical assistance on 300,000 acres of farmland within the former Great Black Swamp region to reduce an estimated 10,000 pounds of total phosphorus from entering the Maumee River watershed.[211]
Due to the loss of habitat, biodiversity has suffered significantly since the conversion of the Great Black Swamp into agriculture. Species that are threatened with extinction include the Spotted turtle, which has declined significantly over the years, but is receiving serious protection.[212]The Copperbelly water snake is another species that has suffered significant population losses in the former Great Black Swamp region. Today, this species inhabits just 50km2 (20 sq miles) of remnant swamp forest in Ohio, Michigan, and Indiana, with experts estimating that between 40 and 100 individuals remain.[213] The Piping plover, the Loggerhead shrike, and the Northern harrier are other species that need protection, and are considered Endangered in Ohio.[214]Wetland conservation projects focus on restoring habitats that suit the needs of these species in the best way possible.
Black bears were extirpated in most of Ohio by the 1850s, and the last one was killed in the Great Black Swamp by 1881, in Paulding County. They were discovered in the State in the 1970s, having entered from Pennsylvania and West Virginia, and since then, the Ohio Department of Natural Resources (ODNR) has been conducting surveys on their population, which numbers between 50 and 100 bears. While almost all of the black bear sightings in the State occur along the borders with Pennsylvania and West Virginia, only 4 sightings were made between 1993 and 2022 in the former Great Black Swamp region, in Fulton and Seneca Counties.[215] The ODNR lists the black bear as an Endangered Species in Ohio and makes it illegal to hunt them.
The Sandhill crane was extirpated in Ohio by the early 20th century, but has slowly made a comeback across the State. Most recently, the Ohio DNR, the International Crane Foundation, and the Ohio Bird Conservation Initiative counted 184 Sandhill cranes across 4 counties in the former Great Black Swamp region (Fulton, Lucas, Ottawa, and Sandusky) in 2023 and 2024 during the nesting season.[216] They are listed as Threatened by the Ohio DNR and receive protection in the State.[217] Hunting and habitat loss killed most of the Whooping crane population in North America by the late 19th and early 20th centuries. The Whooping crane was thought to have been a resident of the Great Black Swamp region, especially since it still uses the Mississippi Flyway to this day. Despite the Ohio Bird Records Committee believing that the species deserved inclusion on the official Ohio list of historic bird species, its historic presence cannot be confirmed because of poor record keeping practices in the late 19th and early 20th centuries, which included losing and/or destroying written and photographic documentation, crane skins, and even cranes that had been stuffed by taxidermists.[218] Whooping cranes are rarely sighted, either in the former Swamp region or the rest of Ohio.[219]
Indigenous peoples descended from northwest Ohio, today
Indigenous peoples in the United States often refer to themselves as American Indians or Native Americans, with preferred usage depending on the individual.[220] This preference also extends to the names of their nations: Wyandot, Chippewa, Seneca, and other groups who called the Great Black Swamp region home. Their histories are intertwined with that land, which shaped their languages and cultures for thousands of years before European contact.
After nearly two centuries of the U.S. government mishandling the Indian reservation system and initiatives like the Indian Relocation Act of 1956, Indigenous peoples are working to secure the return of thousands of acres of land taken from their ancestors in the 19th century. The September 2023 addition of the Hopewell Ceremonial Earthworks (central Ohio) to the UNESCOWorld Heritage Site list encouraged Indigenous land rights efforts. Following this, in October 2023, the Native American Indian Center of Central Ohio raised funds to purchase rural land intended to foster Native American life and activities.[221]
In 2024, a 12-episode podcast, "The Ohio Country", premiered on WYSO radio to discuss Ohio Indigenous history, and discuss with Indigenous peoples about their stories, including how tribal descendants are reviving their languages and renewing their cultures and working to restore their historic bonds to Ohio.[222] Indigenous people who returned to Ohio in the past include Mother Solomon, who moved from the Wyandot territory in Kansas to an area north of the Upper Sandusky on the Sandusky River in 1865.
Stories shared by Indigenous peoples descended from northwest Ohio directly challenge historical denials, such as the 1982 WBGU-TVPBS documentary's false claim that they abandoned the Great Black Swamp due to mosquitoes and fear of the land.[164] Historical records confirm Indigenous groups did not willingly leave the Swamp region; they were forcibly removed by the U.S. government under the Indian Removal Act. Even Charles Dickens noted their deep reluctance to leave their lands and the graves of their loved ones when he met them in 1842.[78] They were opposed to removal because Northwest Ohio and the Swamp region had always been their home. They were forced from Ohio by overcrowded steamboats, wagons, horseback, or by walking the entire way to Indian Territory west of the Mississippi River.[223] Problems arose, however, when the Wyandot people arrived in Kansas in 1843, and learned they would not be fully compensated for the lands they sold to the U.S. government, and that there actually was no land for them to settle or purchase in Kansas.[224]
Efforts are underway in the 2020s to return an estimated 6,500 Indigenous remains in Ohio museums and collections to their respective nations for reburial, as mandated by the Native American Graves Protection and Repatriation Act (NAGPRA).[225] In 2022, five potential burial sites were identified in Rossford, Wood County near an elementary school property where ten Indigenous mass graves were discovered in 1962.[226] Although 2022 archaeological tests found no human remains, the school is still slated for demolition in 2025 and replacement with an urban forest and trails.[227] Because of constant construction projects breaking ground, efforts to identify possible Indigenous graves are ongoing in northwest Ohio. In 2003, human bones dating to 1600 B.C.E. (over 3,600 years old), found at an Ottawa County construction site in the former Great Black Swamp, were given a reburial ceremony led by four indigenous people from the Five States Alliance of First Americans.[228]
In August 2025, NAGPRA's inventory recorded a total of 1,257 Indigenous remains recovered from 9 counties within the former Great Black Swamp region: Allen County (66 remains), Fulton County (13 remains), Hancock County (2 remains), Henry County (3 remains), Lucas County (5 remains), Ottawa County (490 remains), Putnam County (3 remains), Sandusky County (634 remains), and Wood County (41 remains).[229] In addition to the NAGPRA inventory, the National Park Service and the U.S. Department of the Interior released a statement in March 2025, stating they had completed an inventory of Indigenous human remains from Wood County, identifying at least 1,399 individuals and 4,661 associated funerary objects dating back centuries.[230]
Indigenous nations from the Great Black Swamp and Lake Erie regions, including Ontario, suffered the psychological trauma of losing their ancestral lands and burial places.[231] These graves were central to their cultural and spiritual beliefs, representing a sacred, continuous bond with ancestors and loved ones that was violently severed. American history, policymakers, and government leaders have consistently minimized, dismissed, and ignored this historical trauma. Increasing public awareness and education about Indigenous history in Ohio and the Great Black Swamp helps restore a more complete memory of the state's past.[223]
Recognition is increasing of Indigenous traditional ecological knowledge, and its benefits for managing land and nature.[235] These concepts are very different from the commercial views of water as just another resource to thoughtlessly exploit without limit.[236] The National Association of Wetland Managers and the U.S. EPA publish handbooks to guide States and Indigenous nations on how to manage and protect wetlands.[237]
Recent legal challenges create obstacles for wetland protection in the U.S., often when it involves a person's right on how to use the land they own, such as in the 2023 Supreme Court ruling in "Sackett v. EPA". In March 2025, the Natural Resources Defense Council (NRDC) released a report discussing how the Supreme Court ruling on "Sackett v EPA" threatens to remove protections for existing wetlands in the U.S. It states tens of millions of acres of wetlands are now vulnerable to pollution and destruction following the ruling.[238]
In other countries, wetlands like the former Great Black Swamp face the threat of development. They include the Congo Peatlands in the Cuvette Centrale, which are the largest tropical swamp peatlands in the world and cover 16.7 million hectares (41 million acres).[239] The Peatlands store 30 billion metric tonnes of carbon in the peat.[240] In 2025, the government of the Democratic Republic of the Congo launched bids for the rights to drill for oil and gas in its country, including within the Congo Peatlands.[241] A growing logging industry, some of it illegal and financed by entrepreneurs in other countries, also threatens to destroy the biodiversity of the Peatland swamps, and complicate the lives of the peoples who have inhabited the region, and have called it home, for countless centuries.[242]
A photo of a buoy used for harmful algal bloom monitoring and research in the Western Basin of Lake Erie. This data helps scientists and Ohio communities forecast and prepare for harmful algal bloom events.
The Center for Great Lakes and Watershed Studies at Bowling Green State University (BGSU) is educating the public about wetlands and water, and addressing critical issues affecting Ohio, Lake Erie, and the former Great Black Swamp region.[243] In October 2025, a program on WBGU-TVPBS interviewed scientists from the center to discuss ways of protecting Ohio's water quality and public health from algal blooms, ways of restoring wetlands, and applying the lessons they learn in Ohio in other parts of the world.[244]
As the shallowest and warmest of the Great Lakes, Lake Erie is experiencing more frequent harmful algal blooms (HABs). Increased organic nitrogen input encourages Microcystis blooms and toxin production.[245] Rising temperatures are causing HABs to last longer.[246] To manage these threats, the National Oceanic and Atmospheric Administration (NOAA) monitors HABs, utilizing satellites, field observations, models, buoys, and public health reports.[247] NOAA provides hypoxia forecasts to alert decision-makers to cold, hypoxic upwellings near the shore.[248] Such comprehensive measures are essential due to the lack of wetlands and increasing pollution.
↑ Wright, H. E., Jr., and D. G. Frey, editors. The Quaternary of the United States. Princeton University Press, 1965, pgs. 76, 89-90.
↑ Woods, A.J. et al. "Ecoregions of Indiana and Ohio". U.S. Environmental Protection Agency and U.S. Geological Survey, WEB: last updated May 27, 2025.
↑ Killey, Myrna M. "Illinois' Ice Age Legacy". Geoscience Education Series 14, Illinois Department of Natural Resources, Illinois State Geological Survey, 2007, pg. 17.
↑ Kappler, Charles J., compiler and editor. "Treaty with the Wyandot, Etc., 1795". Indian Affairs: Laws and Treaties, Vol. 2 (Treaties), Washington, D.C.: The Senate Committee on Indian Affairs, 1904, pgs. 39–45. | Royce, Charles C., compiler. "Schedule of Indian Land Cessions (Cessions 15, 18, 20)". Indian Land Cessions in the United States, Eighteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1896–'97, J.W. Powell, Director. Washington, D.C., pgs. 654–655.
↑ Kappler, Charles J., compiler and editor. "Treaty with the Ottawa, Etc., 1807". Indian Affairs: Laws and Treaties, Vol. 2 (Treaties), Washington, D.C.: The Senate Committee on Indian Affairs, 1904, pgs. 92–95. | Royce, Charles C., compiler. "Schedule of Indian Land Cessions (Cession 66)". Indian Land Cessions in the United States, Eighteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1896–'97, J.W. Powell, Director. Washington, D.C., pgs. 674–675.
↑ Kappler, Charles J., compiler and editor. "Treaty with the Chippewa, Etc., 1808". Indian Affairs: Laws and Treaties, Vol. 2 (Treaties), Washington, D.C.: The Senate Committee on Indian Affairs, 1904, pgs. 99–100. | Royce, Charles C., compiler. "Schedule of Indian Land Cessions (Cession 70)". Indian Land Cessions in the United States, Eighteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1896–'97, J.W. Powell, Director. Washington, D.C., pgs. 676–677.
↑ NPS.GOV. "Person: Tecumseh". National Park Service, U.S. Department of the Interior, WEB: last updated November 12, 2023.
↑ Kappler, Charles J., compiler and editor. "Treaty with the Wyandot, Etc., 1817". Indian Affairs: Laws and Treaties, Vol. 2 (Treaties), Washington, D.C.: The Senate Committee on Indian Affairs, 1904, pgs. 145–155. | Royce, Charles C., compiler. "Schedule of Indian Land Cessions (Cessions 87 & 88)". Indian Land Cessions in the United States, Eighteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1896–'97, J.W. Powell, Director. Washington, D.C., pgs. 684–685.
↑ American Board of Commissioners for Foreign Missions. The Missionary Herald ... for the Year 1830. Boston: Printed for the American Board of Commissioners for Foreign Missions, Vol. XXVI, 1830, pg. 13.
↑ Kappler, Charles J., compiler and editor. "Treaty with the Ottawa, Etc., 1831". Indian Affairs: Laws and Treaties, Vol. 2 (Treaties), Washington, D.C.: The Senate Committee on Indian Affairs, 1904, pgs. 335–339. | Royce, Charles C., compiler. "Schedule of Indian Land Cessions (Cessions 167, 168)". Indian Land Cessions in the United States, Eighteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1896–'97, J.W. Powell, Director. Washington, D.C., pgs. 734–735.
↑ Kappler, Charles J., compiler and editor. "Treaty with the Wyandot, 1832". Indian Affairs: Laws and Treaties, Vol. 2 (Treaties), Washington, D.C.: The Senate Committee on Indian Affairs, 1904, pgs. 339–341. | Royce, Charles C., compiler. "Schedule of Indian Land Cessions (Cession 171)". Indian Land Cessions in the United States, Eighteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1896–'97, J.W. Powell, Director. Washington, D.C., pgs. 734–735.
↑ Kappler, Charles J., compiler and editor. "Treaty with the Ottawa, 1833". Indian Affairs: Laws and Treaties, Vol. 2 (Treaties), Washington, D.C.: The Senate Committee on Indian Affairs, 1904, pgs. 392–394. | Royce, Charles C., compiler. "Schedule of Indian Land Cessions (Cession 183)". Indian Land Cessions in the United States, Eighteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1896–'97, J.W. Powell, Director. Washington, D.C., pgs. 748–749.
1 2 INDIANAMAP-INMAP.HUB.ARCGIS.COM. "Presettlement Land Cover IDNR 2016". Indiana Geographic Information Office, Indiana State Government, WEB: last updated December 18, 2024.
↑ Crosby, A. Virgin Soil Epidemics. The William and Mary Quarterly, 1976, p. 290. | Richter, D. Facing East from Indian Country: A Native History of Early America. Harvard University Press, 2001, p. 60. | Calloway, C. The Shawnees and the War for America. Viking Adult, 2007, pp. 6–7.
↑ Biddle, Dan. "Ohio's 'Black Laws'". Special Feature, Equal Justice Initiative, WEB: pub. April 1, 2025.
↑ NPS.GOV. "Network to Freedom". National Park Service, U.S. Department of the Interior, WEB: Updated February 12, 2025.
↑ Network to Freedom. "Visit Underground Railroad Locations". Network to Freedom, National Park Service, U.S. Department of the Interior, WEB: updated August 18, 2025.
↑ WGTE Public Media. "Cornerstones: the Irish in Toledo". WGTE Public Documentaries: Toledo Stories. Toledo Lucas County Public Library Collections, October 8, 2003.
↑ WGTE Public Media."Cornerstones: the Germans". WGTE Public Documentaries: Toledo Stories. Toledo Lucas County Public Library Collections, November 14, 2002.
↑ Boberg, Alice; Wroblewski, Ralph. "Part Two: Polish Immigration to the United States". Polish Americans and their Communities of Cleveland. Cleveland Ethnic Heritage Studies, Cleveland State University, 1997, Section: "Economic Immigration: 1865-1920's – Polish Historical and Economic Backgrounds", ISBN978-1-936323-13-5
↑ American Society of Mechanical Engineers (ASME). "Buckeye Steam Traction Ditcher". American Society of Mechanical Engineers. Hancock Historical Museum Association, Findlay, Ohio, August 5, 1988.
↑ 1920 Fourteenth Census of the United States. "Drainage 1920 United States". Dept. of Commerce, Government Printing Office, 1920.
↑ ASME.ORG "Buckeye Steam Traction Ditcher". The American Society of Mechanical Engineers, Hancock Historical Museum Association, Findlay, OH, August 5, 1988.
↑ Carter, M.R. "Ch: Conservation Tillage". Encyclopedia of Soils in the Environment, edited by Daniel Hillel. Academic Press, 2005, 1:306–311. ISBN978-0-12-348530-4
Sampson, H.C. (1930). "Succession in the swamp forest formation in northern Ohio". Ohio Journal of Science. 30: 340–357.
Kaatz, M.R. (1955). "The Black Swamp: A Study in Historical Geography". Annals of the Association of American Geographers. 45 (1): 1–35. doi:10.1111/j.1467-8306.1955.tb01481.x.
Further reading
Out of the Wilderness, History of the Central Mennonite Church," 1835–1960. O. Grieser and E. Beck, The Dean Hicks Company, Grand Rapids Michigan, 1960.
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