president james madison recommended a series of coastal defenses in a message to congress on december 5, 1815. this began a system of forts known as the "third coastal defense system". congress agreed and construction began on these forts in 1816. one of the locations selected was in charleston harbor. in 1829 construction began on a shoal in the harbor about west of fort moultrie. over the next 16 years a artificial island was created using of rock and stone. when completed it was designed to house 650 officers and soldiers with 135 guns mounted on three rows, one above the next. all the guns would point towards the harbor. it was named for brigadier general thomas sumter, a revolutionary war hero.