before the French and Indian war the british didn't really enforce their policys on the colony's so they could basically trade and sell goods however they want. But after the war the british were in massive debt so they needed money, which led to them being more strict and adding the stamp act, tea act, navigation acts, and the intolerable acts. Colonists were angered by this so they started a movement called no taxation without representation. Another event that led to the revolution was the boston massacre were british troops opened fire on some angry colonists. Sorry I don't know exactly how slaves contributed
