Final answer:
Enslaved and free African Americans supported the American colonies during the Revolutionary War primarily for the chance to gain freedom and economic opportunities, with many joining British forces after promises of immediate emancipation.
Step-by-step explanation:
Enslaved and free black people supported the American colonists' war effort during the American Revolutionary War primarily for economic opportunities and promises of freedom. Many African-American slaves wanted to secure their freedom and saw the Revolution as an opportunity to demand or fight for this right. Moreover, the British offered immediate emancipation to those willing to join their cause, as exemplified by Lord Dunmore's Proclamation in 1775, which encouraged southern slaves to fight on the British side in exchange for freedom. The Patriot side also had African Americans fighting in hopes of freedom or economic advancements. The actions of these individuals during the war forced consideration of the contradictions inherent in a fight for liberty underpinned by slavery.