When American colonists took up arms in a battle for independence starting in 1775, that fight for freedom excluded an entire race of people—African Americans. On November 12, 1775, General George Washington decreed in his orders that “neither negroes, boys unable to bear arms, nor old men” could enlist in the Continental Army.

Two days after the patriots’ military leader banned African Americans from joining his ranks, however, Black soldiers proved their mettle at the Battle of Kemp’s Landing along the Virginia coast. They captured an enemy commanding officer and proved pivotal in securing the victory—for the British.

After the battle, Lord Dunmore, the royal governor of Virginia who had been forced to flee the capital of Williamsburg and form a government in exile aboard the warship HMS Fowey, ordered the British standard raised before making a startling announcement. For the first time in public he formally read a proclamation that he had issued the previous week granting freedom to the enslaved workers of rebels who escaped to British custody.

Dunmore’s Proclamation was “more an announcement of military strategy than a pronouncement of abolitionist principles,” according to author Gary B. Nash in The Unknown American Revolution: The Unruly Birth of Democracy and the Struggle to Create America. The document not only provided the British with an immediate source of manpower, it weakened Virginia’s patriots by depriving them of their main source of labor.

Much like Lincoln’s Emancipation Proclamation, however, Dunmore’s Proclamation was limited in scope. Careful not to alienate Britain’s white Loyalist allies, the measure applied only to enslaved workers whose masters were in rebellion against the Crown. The British regularly returned enslaved people who fled from Loyalist masters.

Dunmore’s Proclamation inspired thousands of enslaved people to risk their lives in search of freedom. They swam, dog-paddled and rowed to Dunmore’s floating government-in-exile on Chesapeake Bay in order to find protection with the British forces. “By mid-1776, what had been a small stream of escaping slaves now turned into a torrent,” wrote Nash. “Over the next seven years, enslaved Africans mounted the greatest slave rebellion in American history.”

Among those enslaved people making a break for freedom were eight belonging to Peyton Randolph, speaker of the Virginia House of Burgesses, and several belonging to patriot orator Patrick Henry who apparently took his famous words—“Give me liberty, or give me death!”—to heart and fled to British custody. Another runaway who found sanctuary with Dunmore was Harry Washington, who escaped from Mount Vernon while his famous master led the Continental Army.

Dunmore placed these “Black Loyalists” in the newly formed Ethiopian Regiment and had the words “Liberty to Slaves” embroidered on their uniform sashes. Since the idea of runaway enslaved people armed with guns stirred terror even among white Loyalists, Dunmore placated the slaveholders by primarily using the runaways as laborers building forts, bridges and trenches and engaging in trades such as shoemaking, blacksmithing and carpentry. Women worked as nurses, cooks and seamstresses.

As manpower issues grew more dire as the war progressed, however, the British army became more amenable to arming formerly enslaved people and sending them into battle. General Henry Clinton organized an all-Black regiment, the “Black Pioneers.” Among the hundreds of runaway enslaved people in its ranks was Harry Washington, who rose to the rank of corporal and participated in the siege of Charleston.

On June 30, 1779, Clinton expanded on Dunmore’s actions and issued the Philipsburg Proclamation, which promised protection and freedom to all enslaved people in the colonies who escaped from their patriot masters. Black men captured fighting for the enemy, however, would be sold into bondage.

According to Maya Jasanoff in her book Liberty’s Exiles: American Loyalists in the Revolutionary World, approximately 20,000 Black enslaved men joined the British during the American Revolution. In contrast, historians estimate that only about 5,000 Black men served in the Continental Army.

As the American Revolution came to close with the British defeat at Yorktown in 1781, white Loyalists and thousands of their enslaved people evacuated Savannah and Charleston and resettled in Florida and on plantations in the Bahamas, Jamaica and other British territories throughout the Caribbean. The subsequent peace negotiations called for all enslaved people who escaped behind British lines before November 30, 1782, to be freed with restitution given to their owners.

In order to determine which African Americans were eligible for freedom and which weren’t, the British verified the names, ages and dates of escape for every runaway enslaved person in their custody and recorded the information in what was called the “Book of Negroes.”

With their certificates of freedom in hand, 3,000 Black men, women and children joined the Loyalist exodus from New York to Nova Scotia in 1783. There the Black Loyalists found freedom, but little else. After years of economic hardship and denial of the land and provisions they had been promised, nearly half of the Black Loyalists abandoned the Canadian province.

Approximately 400 sailed to London, while in 1792 more than 1,200 brought their stories full circle and returned to Africa in a new settlement in Sierra Leone. Among the newly relocated was the formerly enslaved worker of the newly elected president of the United States—Harry Washington—who returned to the land of his birth.