Constitution Island

Formerly known as Martelaer’s Rock, Constitution Island is the site of the earliest Revolutionary War fortifications in the Hudson Valley. Taken briefly by the British in 1777, the island was reoccupied by American forces in 1778 and made an integral part of Fortress West Point. The island was bequeathed to the military academy in 1909 and has been administered by the Army ever since. Beginning in 1775, engineers built Fort Constitution on the island to guard the sharp S‑curve in the river opposite West Point—an area George Washington considered essential to preventing the British from cutting New England off from the other colonies. Although the British briefly seized the island in 1777, American forces reoccupied it in 1778 and integrated it into Fortress West Point, whose defenses—including the famous Great Chain—made the Hudson impassable to British warships.