Final answer:
The battle that proved to the French that the Americans could win the Revolutionary War was Yorktown.
Step-by-step explanation:
The battle that proved to the French that the Americans could win the Revolutionary War was Yorktown. During this battle in 1781, General George Washington and the French army under the command of General Rochambeau trapped the British army led by General Cornwallis in Yorktown, Virginia. The American and French forces combined their strength to lay siege to the British, ultimately forcing their surrender. This pivotal victory led to increased French support and played a crucial role in the ultimate American victory in the war.
Learn more about Revolutionary War battles