Slavery had a large impact on the course of the American Revolution, especially in the southern campaignes.
As the American Revolution spread, the slaves on plantation sided with whatever group promised the most freedom. For the most part, this was the Brtiish Expeditionary Force. The British actively recruited slaves from Patriot masters promising freedom when the war ended. Thousands of runaway followed the British Army during the war hoping to secure freedom. The success of the British and the horrific losses from disease forced Washington to agree to allow blacks into his ranks. By the wars end, the Continental Army was the most racially integrated American Army until Vietnam.
As the war began to end, blacks who had served the British during the war sough passage to other British colonies knowing that their Patriot masters would want them back. 4,000 of them recieved this as the British evacuated New York at the wars end.
At the end of the war, the movement to abandon slavery gained traction in New England. The beginning of European immigration to the factory towns of New England did away with the need for slave labor while the south clung to slavery as a source of wealth, status, and work.