Having withdrawn from Boston after an unsuccessful campaign, the British now focused on capturing New York City. General Sir William Howe, with the services of his brother, Admiral Lord Howe, began amassing troops on Staten Island in July 1776. General Washington, with a smaller army of about 19,000 men, was uncertain where the Howes intended to strike. He unwittingly violated a cardinal rule of warfare and divided his troops about equally in the face of a stronger opponent. The Continental Army was split between Long Island and Manhattan, thus allowing the stronger British forces to engage only one half of the smaller Continental Army at a time.
When Howe moved to encircle Washington's army in October, the Americans again fell back, and a battle at White Plains was fought on October 28, 1776. Once more Washington retreated, but Howe, instead of aggressively pursuing the withdrawal, returned to Manhattan and captured Fort Washington in mid November, taking almost 3,000 prisoners. Four days later, Fort Lee, across the Hudson River from Fort Washington, was also taken.
The British gained control of New York harbor and the surrounding agricultural areas, and held New York City and Long Island until the war ended in 1783. The Americans had suffered significant casualties and lost important supplies, but Washington managed to withdraw the core of his army and avoided the decisive confrontation that could have ended the war.
General Lord Cornwallis continued to chase Washington's army through New Jersey until the Americans withdrew across the Delaware River into Pennsylvania in early December. With the campaign at an apparent conclusion for the season, the British entered winter quarters. They controlled much of New York and New Jersey and were in a good position to resume operations in the spring, with the rebel capital of Philadelphia in striking distance.
The outlook of the Continental Army — and thus the revolution itself — was bleak. "These are the times that try men's souls," wroteThomas Paine, who was with the army on the retreat. The army had dwindled to fewer than 5,000 men fit for duty and would be reduced to 1,400 after enlistments expired at the end of the year. Spirits were low, popular support was wavering, and Congress had abandoned Philadelphia in despair.
Washington reacted by taking the offensive, stealthily crossing the Delaware on Christmas night and capturing nearly 1,000 Hessians at the Battle of Trenton on December 26, 1776. Cornwallis marched to retake Trenton but was outmaneuvered by Washington, who successfully attacked the British rearguard at Princeton on January 3, 1777. Washington then entered winter quarters at Morristown, New Jersey, having retaken most of the colony from the British.
Schecter, Barnet. The Battle for New York: The City at the Heart of the American Revolution. 2002. (website)
Wood, W. J. Battles of the Revolutionary War, 1775-1781. Originally published Chapel Hill, N.C.: Algonquin, 1990; reprinted by Da Capo Press, 1995. ISBN 0-306-80617-7 (paperback); ISBN 0-306-81329-7 (2003 paperback reprint).