On September 21, 1775, John Berrien used the name "Constitution Fort" for the first time in an official document of the New York Provincial Congress.

Gen. George Washington was appointed by the Continental Congress to work with the New York Provincial Congress to make plans on how the Hudson River should be fortified against the British. Subsequently, Bernard Romans, an engineer, was appointed to begin the construction of the large fort on the island which was to be named "Fort Constitution." When Sir Henry Clinton's British troops went up the Hudson River from New York City in 1777, the small group of American soldiers encamped on the island destroyed as much as possible of the unfinished fort and fled. British troops occupied the island for twenty days. Fort Constitution was never rebuilt.

West Point was the new site of the forts built by the Americans in January 1778 and where a chain was stretched across the river to Constitution Island, Col. Thaddeus Kosciusko directed the construction at West Point and, on Constitution Island, built three redoubts and a battery to protect the east end of the great chain. A large barracks was built and American soldiers were stationed on the island until December 20, 1783 when Gen. Washington's personal "lifeguard" was disbanded there.