This is an old postcard of Fort Walker. You can see the ruins at the end of Fort Walker Drive. There is a historical marker.
Fort Walker was at the mouth of Port Royal Sound facing Fort Beauregard on the other side of the Sound.
They were built using slave labor to protect Port Royal and defend against the Union blockade. Port Royal was a very important port for the Antebellum South.
The Battle of Port Royal, November 1861, was one of the sea battles of the Civil War. The Union took Port Royal and renamed it Fort Welles after then Secretary of the Navy Gideon Welles.