Question: who led an attack that allowed for american victory at yorktown?
Answer: George Washington, Comte de Rochambeau

The Siege of Yorktown , also known as the Battle of Yorktown , the Surrender at Yorktown , German Battle or the Siege of Little York , ending on October 19 , 1781 , at Yorktown , Virginia , was a decisive victory by a combined force of American Continental Army troops led by General George Washington and French Army troops led by the Comte de Rochambeau over a British Army commanded by British peer and Lieutenant General Charles Cornwallis . The culmination of the Yorktown campaign , the siege proved to be the last major land battle of the American Revolutionary War in the North American theater , as the surrender by Cornwallis , and the capture of both him and his army , prompted the British government to negotiate an end to the conflict . The battle boosted faltering American morale and revived French enthusiasm for the war , as well as undermining popular support for the conflict in Great Britain .