On October 19, 1781, what decisive event effectively ended the American Revolutionary War?

The British surrender at Yorktown is the answer. At Yorktown, Virginia, British General Charles Cornwallis surrendered to the combined American and French campaign led by George Washington, with French ground and naval support helping collapse Britain’s major southern campaign during the American Revolutionary War.

The Trap at Yorktown

Cornwallis’s army was trapped on the Virginia peninsula after American and French forces closed in by land while the French navy blocked escape or reinforcement by sea. The naval turning point came after the Battle of the Chesapeake, which helped keep British ships from relieving the army at Yorktown. Marquis de Lafayette had already helped contain Cornwallis in Virginia before Washington and the French commander, Comte de Rochambeau, brought the main allied force into position.

Washington, France, and the Siege

George Washington commanded the American army during the final Yorktown campaign, while Rochambeau’s French ground forces played a major role in the siege. The cooperation between American troops, French soldiers, and the French navy made Yorktown different from an ordinary battlefield victory. Cornwallis’s position became impossible to hold once the allied siege lines tightened and British support by sea was cut off.

Why the Surrender Was Decisive

Cornwallis surrendered at Yorktown on October 19, 1781, ending Britain’s last major attempt to win the war through a large southern army. The surrender did not officially end the American Revolution by treaty, but it effectively ended major fighting and pushed Great Britain toward peace negotiations. The war formally ended two years later with the Treaty of Paris in 1783, when Britain recognized United States independence.