Hessian Lieutenant General Wilhelm von Knyphausen and a force of 3,000 Hessian mercenaries and 5,000 Redcoats lay siege to Fort Washington at the northern end and highest point of Manhattan Island.

Throughout the morning, Knyphausen met stiff resistance from the Patriot riflemen inside the fort, but by afternoon, the Patriots were overwhelmed, and the garrison commander, Colonel Robert Magaw, surrendered. Nearly 3,000 Patriots were taken prisoner, and valuable ammunition and supplies were lost to the Hessians. The prisoners faced a particularly grim fate: Many later died from deprivation and disease aboard British prison ships anchored in New York Harbor.

Among the 53 dead and 96 wounded Patriots were John and Margaret Corbin of Virginia. When John died in action, his wife Margaret took over his cannon, cleaning, loading and firing the gun until she too was severely wounded. The first woman known to have fought for the Continental Army, Margaret survived, but lost the use of her left arm.

Two weeks earlier, one of Magaw’s officers, William Demont, had deserted the Fifth Pennsylvania Battalion and given British intelligence agents information about the Patriot defense of New York, including details about the location and defense of Fort Washington. Demont was the first traitor to the Patriot cause, and his treason contributed significantly to Knyphausen’s victory.

Fort Washington stood at the current location of Bennett Park in the Washington Heights neighborhood of New York City, near the George Washington Bridge, at the corner of Fort Washington Avenue and 183rd Street. Fort Washington Park and Fort Washington Point lay beneath the site along the Hudson River.