Fort Strong is a former U.S. Army Coast Artillery fort that occupied the northern third of Long Island in Boston Harbor. The island had a training camp during the American Civil War, and a gun battery was built there in the 1870s. The fort was built in 1893-1906 during the Endicott period of expansion in U.S. coast defense, and was part of the Coast (later Harbor) Defenses of Boston. Formerly, it was also known as Long Island Military Reservation. Before World War I, a large station for handling submarine mines was added to the fort's defenses. Prior to World War I the fort was probably manned by over 1,000 soldiers. During World War II, two batteries of 3-inch guns (Basinger and Stevens) defended channel minefields, but the big guns and other 3-inch batteries (except for the AA guns) were