What was the mistake British general Charles Cornwallis made that ultimately caused his defeat

One of the major mistakes that British general Charles Cornwallis made, leading to his defeat, was his decision to occupy the town of Yorktown in Virginia. Cornwallis, stationed in the southern colonies during the American Revolutionary War, found himself trapped when American and French forces surrounded his army in Yorktown in 1781.

Cornwallis's blunder was that he had chosen a vulnerable position with only one means of resupply or reinforcement—a nearby British naval fleet. However, the French navy, commanded by Admiral de Grasse, managed to defeat the British navy, thus cutting off Cornwallis's only line of escape or support. This naval success allowed American and French troops to lay siege to the British troops in Yorktown.

Cornwallis's choice to occupy Yorktown was strategic in the short term, as it provided access to the Chesapeake Bay and supply lines to Britain. However, it proved to be a fatal mistake when he underestimated the strength of the American and French armies as well as their coordination with the French fleet. This tactical error ultimately led to the surrender of Cornwallis and his troops on October 19, 1781, marking a significant turning point in the Revolutionary War.