Constitution Island is a 400-acre rocky island separated from the mainland by a reedy marsh. It was originally called Martelaer's Island by the Dutch.
Located in New York, across the Hudson River from West Point, it was the site of Revolutionary War fortifications. Fort Constitution was the name of the fort to be built on the island, to defend against British attacks. In 1777, British troops occupied the uncompleted fort for twenty days.
The following year, under the direction of Colonel Thaddeus Kosciuszko, a great iron chain was built across the river from West Point to the island to prevent British ships from traveling up the Hudson. Soldiers were stationed there to protect the chain until December 1783.
In the 1830s, a successful lawyer from New York City named Henry Whiting Warner bought Constitution Island, and had a summer home there called Good Craig. In 1836, due to financial troubles, Warner moved there permanently with his two daughters, Anna and Susan. He lived there until his death in 1875. His daughters, who became famous writers and taught Bible classes to West Point cadets, continued to live there afterward.
Today, Constitution Island is part of West Point Military Academy, and with the exception of limited guided tours is closed to the public.