These were the all-Black units of the British Marines in America

Enslaved Americans in the War of 1812 found a surprising path to freedom. America and the United Kingdom both enslaved Africans and their descendants, but Brits accepted escaping people. It undercut the U.S. war effort and weakened the economy. Britain upped the ante in April 1814 when it started the Corps of Colonial Marines and actively recruited enslaved people with promises of freedom.

Americans, always wary of a slave revolt and enraged at the loss of "property," protested. Hundreds of enslaved persons earned equal pay, pensions, and other benefits to their Royal Marine brethren. After the war, many achieved freedom and received land in Canada or Trinidad.

America declared war in June 1812 after years of Britain supporting native tribes against American expansion and of it pressing American citizens into British naval service. But Britain, while still vastly stronger than the U.S. at the time, was busy fighting Napoleon.

In April 1814, as British forces took part in the War of the Sixth Coalition, other forces looked for how to win in America when reinforcements were unlikely. As the war shifted from the northern states to the Chesapeake Bay area in Maryland and Virginia, one senior officer, Vice Admiral Alexander Cochrane, came up with actively recruiting enslaved Americans.

The logic flows easily. Americans feared a slave revolt. Americans relied on slave labor. And the British could use the troops. Meanwhile, enslaved people already fled to British forces and ships when they could. If Britain could increase the number of enslaved people escaping, they could help themselves and hurt their enemies.

Cochrane issued a proclamation promising freedom to any enslaved Americans who served in the King's Forces. He ordered 1,000 copies printed and passed out in the Chesapeake area. About 100 escaped people responded by the end of April.

The escapees settled on Tangier Island in the bay. British forces began training a small group of men selected for military service, known as Blue Jackets. Women, children, and those not selected did other work for British forces. The ranks of the combat troops climbed, and, on May 18, the U.K. officially formed its Corps of Colonial Marines.

These men received the same pay, pension and other benefits as their Royal Marine counterparts, as well as the promise of their freedom. The ranks soon climbed to 200 men.

Just two weeks later, Colonial Marines took part in their first raid at Rumley's Gut, where it helped capture an artillery battery.

The American recruits knew the terrain better than the British could hope to learn it. Some had worked the rivers before their escape and knew the waterways well. They quickly gained a reputation for navigating tough terrain and their performance under fire.

They took part in raid after raid, and eventually entered Washington D.C. with other British forces when Britain took the city and burned the White House. Soon after, American defenders repulsed British attackers, including Colonial Marines, at Baltimore.

About 3,600 formerly enslaved people joined the British, and between 550 and 700 trained and served as troops.

But the Colonial Marines' most intense fight actually came after the war. While many took the offer of land in Nova Scotia or Trinidad, some decided to stay in America in Spanish-controlled Florida. They occupied a former British base that became known as Negro Fort.

Gen. Andrew Jackson eventually led a force against that fort. Jackson's forces had the upper hand from the start, but they also got a lucky shot when a cannon firing red-hot balls landed a hit into the fort's powder magazine. It triggered a massive explosion that destroyed the fort and ended the battle.

After the war, America demanded compensation for its "property," and a settlement eventually resulted in Britain paying $1.2 million.