Why did thousands of enslaved Americans join the British, and others the Patriots, in the Revolution?

Because both sides offered freedom to men who would fight for them, and many enslaved people saw a chance to escape. On 7 November 1775 Lord Dunmore, Virginia's royal governor, declared martial law and promised freedom to indentured servants, enslaved people and others who joined the British. It is estimated that 20,000 African Americans joined the British cause as Black Loyalists, and about 9,000 became Black Patriots.

Dunmore was not acting from principle alone. His own force numbered around 300 men, and he hoped the proclamation would bolster it and make colonists fear a general slave uprising so they would abandon the revolution. It prompted between 800 and 2,000 enslaved people to run away and enlist with him. It also raised a furor among Virginia's slave-owning elites. The historian Gary B. Nash argued that it became a major factor in convincing white colonists that reconciliation with Britain was impossible.

The Patriots had a dilemma. Some revolutionary leaders feared that arming Black men would lead to slave rebellions, yet they needed soldiers. Black soldiers made up approximately four percent of the Patriots' numbers, and in 1778 Rhode Island, struggling to recruit white men, enlisted enslaved men in its own regiment.

For many the promise was kept only in part. Many enslaved men who fought gained freedom, but others did not, as some owners reneged on their promises. After the war, the British resettled some of those they had freed in Nova Scotia, and most northern states abolished slavery within two decades.