A monitor is a relatively small warship that is neither fast nor strongly armored but carries disproportionately large guns. They were used by some navies from the 1860s, during the First World War and with limited use in the Second World War.
An ironclad is a steam-propelled warship protected by iron or steel armor plates, constructed from 1859 to the early 1890s. The ironclad was developed as a result of the vulnerability of wooden warships to explosive or incendiary shells. The first ironclad battleship, Gloire, was launched by the French Navy in November 1859 – narrowly pre-empting the British Royal Navy, though Britain built the first completely iron-hulled warships.
USS Agamenticus was one of four Miantonomoh-class monitors built for the United States Navy during the American Civil War. Commissioned as the war was ending in May 1865, the ironclad saw no combat and was decommissioned in September and placed in reserve. The ship was reactivated in 1870, having been renamed Terror the previous year, and was assigned to the North Atlantic Fleet where she served in the Caribbean Sea. The monitor was decommissioned again in 1872 and was sold for scrap two years later. The Navy Department evaded the Congressional refusal to order new ships by claiming that the Civil War-era ship was being repaired while building a new monitor of the same name.
River monitors are military craft designed to patrol rivers.
USS Canonicus was a single-turret monitor built for the United States Navy during the American Civil War, the lead ship of her class. The ship spent most of her first year in service stationed up the James River, where she could support operations against Richmond and defend against a sortie by the Confederate ironclads of the James River Squadron. She engaged Confederate artillery batteries during the year and later participated in both attacks on Fort Fisher, defending the approaches to Wilmington, North Carolina, from December 1864 to January 1865.
USS Tecumseh was a Canonicus-class monitor built for the United States Navy during the American Civil War. Although intended for forthcoming operations against Confederate fortifications guarding Mobile Bay with Rear Admiral David Farragut's West Gulf Blockading Squadron, Tecumseh was temporarily assigned to the James River Flotilla in April 1864. The ship helped to plant obstacles in the river and engaged Confederate artillery batteries in June.
The first USS Miantonomoh was the lead ship of her class of four ironclad monitors built for the United States Navy during the American Civil War. Completed after the war ended in May 1865, the ship made one cruise off the East Coast before she began a voyage across the North Atlantic in May 1866 to conduct a lengthy showing the flag mission in Europe. Miantonomoh was decommissioned upon her return in 1867, but was reactivated two years later and assigned to the North Atlantic Squadron before decommissioning again in 1870. The monitor was sold for scrap three years later as part of a scheme where the Navy Department evaded the Congressional refusal to order new ships by claiming that the Civil War-era ship was being repaired while building a new monitor of the same name.
USS Saugus was a single-turreted Canonicus-class monitor built for the Union Navy during the American Civil War. The vessel was assigned to the James River Flotilla of the North Atlantic Blockading Squadron upon completion in April 1864. The ship spent most of her time stationed up the James River where she could support operations against Richmond and defend against a sortie by the Confederate ironclads of the James River Squadron. She engaged Confederate artillery batteries during the year and later participated in both attacks on Fort Fisher, defending the approaches to Wilmington, North Carolina, in December 1864 – January 1865. Saugus returned to the James River after the capture of Fort Fisher and remained there until Richmond, Virginia, was occupied in early April.
USS Puritan was one of two ocean-going ironclad monitors designed by John Ericsson during the American Civil War of 1861–1865. Launched in mid-1864, construction was suspended sometime in 1865. The Navy Department had specified two twin-gun turrets over Ericsson's protests, but finally agreed to delete the second turret in late 1865. The Navy Department evaded the Congressional refusal to order new ships in 1874 by claiming that the Civil War-era ship was being repaired while building a new monitor of the same name.
The second USS Puritan was a Puritan-class monitor in the United States Navy, constructed in 1882. She was the only ship in her class.
USS Ozark was a single-turreted river monitor built for the United States Navy during the American Civil War. The ship served in the Mississippi River Squadron during the war, and participated in the Red River Campaign shortly after she was commissioned in early 1864. Ozark patrolled the Mississippi River and its tributaries after the end of the campaign for the rest of the war. She was decommissioned after the war and sold in late 1865.
USS Monadnock was one of four Miantonomoh-class monitors built for the United States Navy during the American Civil War. Commissioned in late 1864, she participated in the First in December and Second Battles of Fort Fisher in January 1865. The ship was later assigned to the James River Flotilla on the approaches to the Confederate capitol of Richmond, Virginia and then sailed to Spanish Cuba to intercept the Confederate ironclad CSS Stonewall.
USS Tonawanda was one of four Miantonomoh-class monitors built for the United States Navy during the American Civil War of 1861–1865. Commissioned in 1865 after the war ended in May, the ship was decommissioned at the end of the year, but was reactivated to serve as a training ship at the United States Naval Academy in 1866. She was renamed Amphitrite in 1869 and was decommissioned again in 1872. The monitor was sold for scrap the following year. The Navy Department evaded the Congressional refusal to order new ships by claiming that the Civil War-era ship was being repaired while building a new monitor of the same name.
The Passaic-class ironclad monitors of the U.S. Navy saw service in the U.S. Civil War and the Spanish–American War. The class was an improved version of USS Monitor equipped with a 15-inch Dahlgren gun in place of one of the 11-inch guns.
The Miantonomoh class consisted of four monitors built for the Union Navy during the U.S. Civil War, but only one ship was completed early enough to participate in the war. They were broken up in 1874–1875.
The Canonicus-class monitor was a class of nine monitors built for the Union Navy during the American Civil War. They saw service in the Civil War and the Spanish–American War, although two of them were never commissioned.
The Amphitrite-class monitors were a class of four U.S. Navy monitors ordered in the aftermath of the Virginius affair with Spain in 1873. The four ships of the class included Amphitrite, Monadnock, Terror, and Miantonomoh. A fifth ship originally of the same design, Puritan, was later fitted with extra armor and designated as a unique class.
The Kalamazoo-class monitors were a class of ocean-going ironclad monitors begun during the American Civil War. Unfinished by the end of the war, their construction was suspended in November 1865 and the unseasoned wood of their hulls rotted while they were still on the building stocks. If the four ships had been finished they would have been the most seaworthy monitors in the US Navy. One was scrapped in 1874 while the other three were disposed of a decade later.
The Milwaukee-class monitors were a class of four riverine ironclad monitors built during the American Civil War. Several supported Union forces along the Mississippi River in mid-1864 before participating in the Battle of Mobile Bay in August. Chickasaw and Winnebago bombarded Confederate coastal fortifications during the battle and during subsequent operations as well as engaging the ironclad Tennessee II. The other two ships arrived at Mobile Bay after the battle and all four supported the land attacks on Mobile in March–April 1865. Milwaukee struck a torpedo during this time and sank. The surviving three ships were sold in 1874; Chickasaw was converted into a ferry and survived until 1944 when she was scuttled. Her wreck was discovered in 2004.
