The siege of Yorktown was a decisive Allied victory by the combined forces of the Continental Army commanded by General Washington, the French Army commanded by the General Comte de Rochambeau, and the French Navy commanded by Admiral de Grasse, in the defeat of Cornwallis' British forces. On August 19, the march to Yorktown led by Washington and Rochambeau began, which is known now as the "celebrated march". Washington was in command of an army of 7,800 Frenchmen, 3,100 militia, and 8,000 Continentals. Not well experienced in siege warfare, Washington often referred to the judgment of General Rochambeau and used his advice about how to proceed; however, Rochambeau never challenged Washington's authority as the battle's commanding officer.

By late September, Patriot-French forces surrounded Yorktown, trapped the British Army, and prevented British reinforcements from Clinton in the North, while the French navy emerged victorious at the Battle of the Chesapeake. The final American offensive was begun with a shot fired by Washington. The siege ended with a British surrender on October 19, 1781; over 7,000 British soldiers were made prisoners of war, in the last major land battle of the American Revolutionary War. Washington negotiated the terms of surrender for two days, and the official signing ceremony took place on October 19; Cornwallis claimed illness and was absent, sending General Charles O'Hara as his proxy. As a gesture of goodwill, Washington held a dinner for the American, French, and British generals, all of whom fraternized on friendly terms and identified with one another as members of the same professional military caste.