Fort Delaware State Park
The State of Delaware deeded Pea Patch Island, located in the Delaware River between Delaware and New Jersey, to the U.S. government in 1813, and construction of Fort Delaware was completed around 1859.
Originally built to protect the ports of Wilmington and Philadelphia, Pea Patch Island also became a Union prison camp during the Civil War, housing up to as many as 12,595 Confederate prisoners of war at one time. Manned only briefly during World Wars I and II, the island and fort were finally abandoned and declared surplus property in 1944, when ownership was transferred back to the State of Delaware. Fort Delaware became a state park in 1951.