The Twelve-Mile Circle is an approximately circular arc that forms most of the boundary between Delaware and Pennsylvania. It is a combination of different circular arcs that have been feathered together. [1] [2]
It is nominally a circle with a variable radius of approximately 12 miles (19 km) centered in the town of New Castle, Delaware. [3] In 1750, the center of the circle was fixed at the cupola of the courthouse in New Castle. The Twelve-Mile Circle continues into the Delaware River. A small portion of the circle, known as the "Arc Line," forms part of the Mason-Dixon line in the United States that separates Delaware and Maryland. Two other small portions, although not actually demarcated until 1934, form parts of the boundary between the states of Delaware and New Jersey. [4] Although the Twelve-Mile Circle is often claimed to be the only territorial boundary in the United States that is a true arc, some cities in the South, including Plains, Georgia, [5] have circular boundaries. The Twelve-Mile Circle is, however, the only circular U.S. state boundary. [6]
Its existence dates back to 1681, when King Charles II granted a deed to William Penn north of the already chartered Maryland. Charles created an exception, consisting of 12 miles around New Castle and extending down the peninsula, since these lands were held by the Duke of York, who had won them in conquest from the Dutch colonists. Later, on August 24, 1682, the Duke granted these lands to Penn as well, giving him:
All that the Towne of Newcastle otherwise called Delaware and the fort therein or thereunto belonging scituate lying and being between Maryland and New Jersey in America. And all that Tract of land lying within the Compasse or Circle of twelve miles about the said Towne Scituate lying and being upon the River Delaware and all islands in the said River of Delaware and the said River and Soyle thereof lying North of the Southernmost part of the said Circle of twelve miles about the said Towne. And all that Tract of Land upon Delaware River and Bay beginning twelve miles South from the said Towne of Newcastle otherwise called Delaware and extending South to Cape Lopen [Henlopen]. [7]
The boundaries of the circle were the focal point of the 80-year Penn–Calvert boundary dispute.
The fact that the circle extends into the Delaware River makes for an unusual territorial possession; within the 12-mile circle, all the Delaware River to the low-tide mark on the east (New Jersey) side is territory of the state of Delaware, leaving the river - and bridges - in sole possession of Delaware. Most territorial boundaries that follow watercourses split the water course between the two territories by one of two methods, either by the median line of the watercourse (the Grotian Method, after Hugo Grotius) or, more often, the center of the main flow channel, or thalweg (the lowest point in the stream channel). A similar condition exists between the states of Vermont and New Hampshire. [8]
New Jersey has often disputed this claim, as the rest of its territorial boundaries along the Delaware River are determined by the midline and thalweg methods. In 1813, Delaware's legislature passed an act deeding Pea Patch Island to the United States government, and in 1820 New Jersey disputed that they owned the island since it was primarily on the New Jersey side of the river. Attorney General William Wirt sided with Delaware. [9] In the 1840s, the Pea Patch Island disagreement led to two conflicting circuit court decisions—the circuit of Delaware ruling that the entirety of the river (and its islands) belonged to Delaware, and the circuit in New Jersey ruling that the island had belonged to New Jersey, which had deeded it to Dr. Henry Gale, a citizen of New Jersey. At the recommendation of President James K. Polk, the parties agreed to arbitration, which resulted in a confirmation of Delaware's claim. [10]
The arbitration did not ultimately resolve the dispute, and it has been brought to the Supreme Court of the United States on several occasions (all titled New Jersey v. Delaware ), most notably in 1907, [11] 1934, [12] 1935, [13] and 2008. [14] The court's opinion for the 1934 case contained an extensive history of the claims to this territory, [12] and the 1935 opinion enjoined New Jersey and Delaware from ever disputing their jurisdictions again. [15]
Regardless of the Supreme Court's admonition to the two states against further litigation on this subject, they were back before the court as late as November 2005, when New Jersey's desire to approve plans by BP to build a liquefied natural gas terminal along the New Jersey shore of the Delaware River fell afoul of Delaware's Coastal Zone Act. [16] The court on January 23, 2006, appointed a special master to study the border dispute, [17] and on March 21, 2008, it upheld his report, which largely supported Delaware's authority. [18] Meanwhile, the Delaware House of Representatives considered a (symbolic) bill to call out the National Guard to safeguard the state's interests, while New Jersey legislators made comments about the battleship New Jersey, moored upriver from the site. [19]
There are persistent rumors that David Rittenhouse, the famous astronomer and instrument-maker of Pennsylvania, surveyed the circle around New Castle, but this is likely not correct. The circle was first laid out by surveyors named Taylor and Pierson in 1701. [20] The 1813 "Memoirs of the life of David Rittenhouse" by William Barton surmises that Rittenhouse was involved in such a survey in 1763, based on a letter in which Rittenhouse mentions being paid "for my attendance at New Castle," but there is no clear record of what, exactly, Rittenhouse was paid for. His biographer, Brooke Hindle, guessed that Rittenhouse assisted with latitude or longitude calculations. [21]
Delaware is a state in the Mid-Atlantic and Northeastern region of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey to its northeast, and the Atlantic Ocean to its east. The state's name derives from the adjacent Delaware Bay, which in turn was named after Thomas West, 3rd Baron De La Warr, an English nobleman and the Colony of Virginia's first colonial-era governor.
The Delaware River is a major river in the Mid-Atlantic region of the United States and is the longest free-flowing (undammed) river in the Eastern United States. From the meeting of its branches in Hancock, New York, the river flows for 282 miles (454 km) along the borders of New York, Pennsylvania, New Jersey, and Delaware, before emptying into Delaware Bay.
The Delmarva Peninsula, or simply Delmarva, is a large peninsula on the East Coast of the United States, occupied by the vast majority of the state of Delaware and parts of the Eastern Shore of Maryland and Eastern Shore of Virginia.
The Mason–Dixon line is a demarcation line separating four U.S. states: Pennsylvania, Maryland, Delaware and West Virginia. It was surveyed between 1763 and 1767 by Charles Mason and Jeremiah Dixon as part of the resolution of a border dispute involving Maryland, Pennsylvania, and Delaware in the colonial United States.
New Castle County is the northernmost of the three counties of the U.S. state of Delaware. As of the 2020 census, the population was 570,719, making it the most populous county in Delaware, with nearly 60% of the state's population of 989,948. The county seat is Wilmington, which is also the state's most populous city.
New Castle is a city in New Castle County, Delaware, United States. The city is located six miles (10 km) south of Wilmington and is situated on the Delaware River. As of 2020, the city's population was 5,551. New Castle constitutes part of the Delaware Valley or Philadelphia metropolitan area.
David Rittenhouse was an American astronomer, inventor, clockmaker, mathematician, surveyor, scientific instrument craftsman, and public official. Rittenhouse was a member of the American Philosophical Society and the first director of the United States Mint.
Finns Point is a small promontory in Pennsville Township, Salem County, New Jersey, and New Castle County, Delaware, located at the southwest corner of the cape of Penns Neck, on the east bank of the Delaware River near its mouth on Delaware Bay. Due to the wording of the original charter defining the boundaries of New Jersey and Delaware, part of the promontory is actually enclosed within the state of Delaware's border, due to tidal flow and the manner in which the borders between New Jersey and Delaware were first laid out. Therefore, this portion of Finns Point, also called The Baja, is an exclave of Delaware, cut off from the rest of the state by Delaware Bay. The area, the westernmost point in New Jersey, is about 10 miles (16 km) south of the city of Wilmington, and directly across the Delaware River from the New Castle area, and the Delaware River entrance to the Chesapeake & Delaware Canal. Pea Patch Island, part of the state of Delaware, sits in the channel of the river facing the promontory.
In geography, hydrography, and fluvial geomorphology, a thalweg or talweg is the line or curve of lowest elevation within a valley or watercourse. Its vertical position in maps is the nadir in the stream profile.
The Wedge is a 1.068-square-mile tract of land along the borders of Delaware, Maryland and Pennsylvania. Ownership of the land was disputed until 1921; it is now recognized as part of Delaware. The tract was created primarily by the shortcomings of contemporary surveying techniques when the boundaries were defined in the 18th century. It is bounded on the north by an eastern extension of the east–west portion of the Mason–Dixon line, on the west by the north–south portion of the Mason–Dixon line, and on the southeast by the Twelve-Mile Circle around New Castle, Delaware. The crossroads community of Mechanicsville, Delaware, lies within the area today.
The Transpeninsular Line is a surveyed line, the eastern half of which forms the north–south border between Delaware and Maryland. The border turns roughly north from the midpoint of the line towards the Twelve-Mile Circle, which forms much of the remainder of the Delaware land border.
The history of Delaware as a political entity dates back to the early colonization of North America by European settlers. Delaware is made up of three counties established in 1638, before the time of William Penn. Each county had its own settlement history. The state's early colonists tended to identify more closely with their county than Delaware as a whole. Large parts of southern and western Delaware were thought to have been in Maryland until 1767. The state has existed in the wide economic and political circle of the nearby Pennsylvanian city of Philadelphia.
New Jersey v. Delaware, 552 U.S. 597 (2008), is a United States Supreme Court case in which New Jersey sued Delaware, invoking the Supreme Court's original jurisdiction under 28 U.S.C. § 1251(a), following Delaware's denial of oil company BP's petition to build a liquefied natural gas pipeline and loading facility on the New Jersey side of the Delaware River. Delaware denied BP's petition because it violated Delaware's Coastal Zone Act. BP then sought New Jersey's approval of the project. Delaware objected because the construction would require dredging of underwater land within Delaware's borders, which extend to the low-tide mark of the New Jersey shore. BP's proposal had not yet passed New Jersey's approval process when New Jersey and BP filed suit against Delaware.
The New Castle Court House Museum is the center of a circle with a 12-mile radius that defines most of the border between the states of Delaware and Pennsylvania and parts of the borders between Delaware and New Jersey and Maryland.
The Penn–Calvert boundary dispute was a long-running legal conflict between William Penn and his heirs on one side, and Charles Calvert, 3rd Baron Baltimore and his heirs on the other side. The overlapping nature of their charters of land in Colonial America required numerous attempts at mediation, surveying, and intervention by the king and courts of England to ultimately be resolved. Subsequent questions over these charters have also been adjudicated by American arbitrators and the Supreme Court of the United States. The boundary dispute shaped the eventual borders of five U.S. states: Pennsylvania, Maryland, Delaware, New Jersey, and West Virginia.
Artificial Island is a U.S. island located along the eastern shore of the Delaware River, mostly in southwestern New Jersey with a tiny portion inside Delaware's boundaries. It is part of both Lower Alloways Creek Township, Salem County, New Jersey and New Castle County, Delaware. The island is separated from mainland New Jersey by Alloway Creek and Hope Creek. It is called "artificial" since portions of the island are composed of land reclaimed from Delaware Bay.
Arkansas v. Tennessee, 397 U.S. 88 (1970), was a case decided by the United States Supreme Court to settle a dispute between the states of Arkansas and Tennessee as to where a portion of the boundary line between the states should run.
Penn v Lord Baltimore (1750) 1 Ves Sen 444 was a judicial decision of Lord Hardwicke LC in relation to the long-running Penn–Calvert boundary dispute.
The Court said that the question whether the land lay within the State of Kentucky or of Indiana ... and reached the conclusion that the boundary between the states was at low water mark on the northwest side of the river.