National preserve, on Sullivan's Island at the entrance to the harbour of Charleston , South Carolina, U.S. Construction of the fort began in 1829 and was still in progress in 1861, when it became the site of the first engagement of the American Civil War (April 12, 1861).
The national monument, established in 1948, also includes Fort Moultrie, site of an American victory against the British (June 28, 1776) in the American Revolution , when the fort was called Fort Sullivan. The Seminole Indian leader Osceola is buried there.