The siege of Yorktown, also known as the Battle of Yorktown and the surrender at Yorktown, began September 28, 1781, and ended on October 19, 1781, at exactly 10:30 am in Yorktown, Virginia. It was a decisive victory by a combined force of the American Continental Army troops led by General George Washington with support from the Marquis de Lafayette and French Army troops led by the Comte de Rochambeau and a French naval force commanded by the Comte de Grasse over the British Army commanded by British Lieutenant General Charles Cornwallis. The siege of Yorktown was the last major land battle of the American Revolutionary War in North America, and led to the surrender of General Cornwallis and the capture of both him and his army. On September 26, transports with artillery, siege tools, and some French infantry and shock troops from Head of Elk, the northern end of the Chesapeake Bay, arrived, giving Washington command of an army of 7,800 Frenchmen, 3,100 militia, and 8,000 Continentals. Washington planned to use the cover of a moonless night to gain the element of surprise.

To reinforce the darkness, he added silence, ordering that no soldier should load his musket until reaching the fortifications. Facing a hopeless situation, Cornwallis surrendered on October 19, 1781, after a series of unsuccessful British sortie attempts and devastating allied artillery fire. The Battle of Yorktown proved to be the decisive engagement of the American Revolution. The British surrender forecast the end of British rule in the colonies and the birth of a new nation—the United States of America. Outnumbered and outfought during a three-week siege in which they sustained great losses, British troops surrendered to the Continental Army and their French allies. This last major land battle of the American Revolution led to negotiations for peace with the British and the signing of the Treaty of Paris in 1783. Following the surrender, the American and French officers entertained the British officers to dinner. The British officers were "overwhelmed" by the civility their erstwhile foes extended to them, with some French officers offering "profuse" sympathies for the defeat, as one British officer, Captain Samuel Graham, commented.