The largest fort built during the American Civil War , it encompassed an area of 255 acres ( 103 ha ) .
The largest fort built during the American Civil War , it had a perimeter of 3.5 miles ( 5.6 km ) .
The largest fort built during the American Civil War , it encompassed an area of 255 acres ( 103 ha ) and had a perimeter of 3.5 miles ( 5.6 km ) .