Why was the yorktown battle the turning point of the revolutionary

It was not clear at the time that Yorktown was the climax of the war, since the British still occupied key ports such as New York City and Charleston, South Carolina. Sporadic fighting continued after the Yorktown surrender, and Washington believed the war might drag on for another year. 

Ithink the answer is  -the colony was represented by the house of burgesses.i hoped is