Castle Williams

 (1807-1966) - A Second System fort constructed between 1807-1811 to guard the channel between Governors Island and Manhattan Island along with Castle Clinton. Designed and construction supervised by Colonel Jonathan Williams, Chief of Engineers and first Commandant of the United States Military Academy at West Point. Named Castle Williams in December 1810 after Colonel Williams who also designed Castle Clinton. Abandoned by the U.S. Army in 1966.

History
Constructed as a three-tier round masonry fort between 1807-1811. Designated as a Castle because of the shape and the materials, The walls were constructed from red Newark sandstone with a granite parapet. This fort served as a prototype for casemated masonry forts of the Second System.

The first two tiers of Castle Williams contained 26 embrasures each, the third tier was meant to house troops but also contained 26 embrasures. Addition gun emplacements were placed along the top of the fort "en Barbette". The fort was originally designed to mount a total of 80 guns and was later modified to mount 102 guns. The embrasures were designed so that an incoming cannonball could not pass between the gun and the embrasure, thus protecting the gun crew.

The sallyport entrance to the fort is crowned by an arch and keystone inscribed with the name and the construction start date (1807) and the completion date (1811).

The strength of Castle Williams, Castle Clinton and Fort Jay provided sufficient protection to New York City during the War of 1812 that the British did not attack.

U.S. Civil War
Castle Williams housed Confederate prisoners of war and political prisoners all during the U.S. Civil War. The fort was originally prepared to house 250 prisoners but by the end of the war, as many as 713 were confined there.

Following the U.S. Civil War the fort continued to be used a prison and as a processing point for Army recruits. The guns remained mounted on the first two tiers for a number of years. Castle Williams continued to be used as a prison up until the U.S. Army left the island in 1966.

Current Status
Must See! Part of Governors Island National Monument.

See Also:
 * Civil War Union Prisons

Sources:
 * , page 555-556.
 * , page 324.

Links:
 * North American Forts - Castle Williams
 * Wikipedia - Castle Williams