The American Revolution was an event in which colonists were revolting against the oppressive British government. As they were revolting, they used the Declaration of Independence as a means to support their views. In the Declaration of Independence, it stated that "all men are created equal" and that they are born with certain "unalienable rights." This concept of all men having the right to life, liberty, and the pursuit of happiness struck home to African-Americans.
After reading/hearing about this declaration, the desire for emancipation (aka being freed from slavery) increased. African-Americans felt that this document clearly outlined their rights as Americans. These men hoped that the success of the American Revolution would result in freedom from slavery.