Final answer:
The French fleet guarded Chesapeake Bay during the Battle of Yorktown, preventing Cornwallis and his troops from escaping by sea.
Step-by-step explanation:
During the Battle of Yorktown, the French fleet played a crucial role by guarding Chesapeake Bay. This strategic position prevented Cornwallis and his troops from escaping by sea, effectively trapping them in Yorktown. As a result, Cornwallis eventually surrendered to the American and French forces.
Learn more about The Battle of Yorktown and the role of the French fleet