Fort Lee, originally Fort Constitution, was a Revolutionary War-era fort located on the crest of the Hudson Palisades in what was then Hackensack Township, New Jersey opposite Fort Washington at the northern end of Manhattan Island. George Washington, then commander of the Continental Army, issued orders to General Mercer to summon all available troops and erect a fort on the west side of the Hudson River. Construction commenced in July 1776 on the new fort, to be called Fort Constitution. The fort was located on the western side of the road that led up the hill from the landing. Concurrently, Fort Washington was being built almost directly across the North River (Hudson River) in New York. On November 20, Howe ordered Cornwallis to capture Fort Lee. The plan was to trap the American army between the Hackensack River and the Hudson River. With a force of 4,000-6,000 British soldiers, Cornwallis crossed the Hudson River in a rainstorm and landed about 6 miles north of the fort and marched south. Washington sent word of the British advance to the Continental Congress and suggested that Philadelphia would likely become the next target. The news came as a shock to many of the delegates, who had failed to grasp how badly the war was going.

Fort Lee was rendered defenseless after Continental Army troops holding Fort Washington were defeated and captured on November 16, 1776. The Royal Navy controlled the Hudson River. General William Howe ordered Charles Cornwallis to "clear the rebel troops from New Jersey without a major engagement, and to do it quickly before the weather changed. In an effort to ambush Washington and crush the rebellion in the wake of the rebel's defeat in the Battle of Brooklyn and the Battle of Fort Washington, Cornwallis marched his men up the cliffs of the Palisades via a rough path, and southward through the Northern Valley. The British were delighted at what they found at the abandoned fort. They found 50 cannon, 1,000 barrels of flour, stores of ammunition, and vast quantities of other supplies left behind by the fleeing Americans. They captured 12 drunk American soldiers in the fort and about 150 other prisoners were taken in the vicinity. Believing he had to the opportunity to strike a decisive blow against the Americans, Cornwallis pursued Washington’s army. The American soldiers then began a hasty retreat west, crossing the Hackensack River at New Bridge Landing and the Passaic River at Acquackanonk Bridge. It was during Washington's retreat that Thomas Paine composed his pamphlet, "The American Crisis", which began with the recognized phrase, "These are the times that try men's souls".