The Battle of Yorktown was the last major battle of the war. It ended the Revolutionary war because the British army stationed at Yorktown, which was led by General Cornwallis, was the last major army in the area. The battle resulted in the British defeat because the French decided at that time to send troops to support the colonist. So when the British were stationed in Yorktown, they were surround on land by the combined forces of the French and Continental armies and their water way escape to the ocean was blocked by the French navy. With no hope of help, and being surrounded, Cornwallis surrendered.