I was surprised to find some slaves freed by the British joined them and were given arms to fight the US, one British officer saying something along the lines of "they are fine fellows all they ask for is rifles and the direction of the enemy"
I have read the British were able to raise a company? of freed slaves but was this used and if so was it effective?
Also did the company take part in the burning of Washington?
For those interested; During the course of the war the British provided freedom and transport to British territory, 4000-5000 were freed.
I suggest picking up a copy of Alan Taylor's The Internal Enemy which is, to my knowledge, the only work that covers the British attempt to form a fifth column of freed slaves as a method of economic warfare during the War of 1812, and during the War for Independence.
However, while there was no large-scale deployment of trained soldiers made of freed slaves on the battlefield, regiments were forming by 1814, and in addition, freed or escaped slaves had offered their services to the British as scouts, guides, "spies," and local experts, which made the hit-and-run raiding of George Cockburn's Chesapeake forces far more effective than they could have been otherwise.
From Taylor:
As they recruited more runaways, the British had to increase their shore raids to obtain more livestock and provisions to feed the fugitives. Thanks to the local expertise of the former slaves, those raids could push deeper into the forested countryside. Black guides and fighters steered the raiding parties around militia ambushes to find hidden herds and secluded farms. The runaways naturally led the raids to the places they knew best: their former neighborhoods, where they could retrieve kin and plunder their former masters.
Cockburn was approached by so many escaped slaves that he fortified Tangier Island, a few miles off the east coast, as a training camp, and there, he inducted free black volunteers as marines, under the command of a white officer, a brevetted ensign William Hammond. As Marines, the freedmen would be under Cockburn's personal command, and would thereby be kept in the local theater, and helpful in making Cokburn's raids more accurate and economically devastating. The alternative was that they would be shipped off to be trained in the West Indies colonial line regiments, eventually intended for service in the war against the United States. Pay for the marines under Cockburn earned $6/month pay and an $8 enlistment bounty, which was comparable to other rates of pay for soldiers on both sides. And while they served under white officers, the freedmen were promoted to corporal and sergeants ranks, for even higher pay.
These men were used in scattered raids and in small skirmishes and other actions, but, to my knowledge - it has been a while since I read Taylor - no large-scale battles, and none were part of the raid on Washington DC.
Way back in the north, in the Michigan territory, Governor William Hull had organized a company of "free black renegadoes from Kentucky" to serve in the Michigan militia. Some of these men were liberated or escaped slaves from British plantations across the Detroit river, in a somewhat ironic reflection of Cockburn's force in the south.
I will be able to give more specific information tomorrow, when I have more of my sources at hand, so please ask follow-ups if you're interested!
As mentioned, Alan Taylor's The Internal Enemy is a good starting point, and I would also recommend Tiya Miles' Dawn of Detroit for more detail on Hull's company of black militia.
In 1793, John Graves Simcoe, Lieutenant-Governor of the province of Upper Canada, enacted a law that would ban slavery in the colony, the first law of its kind in the British Empire. This is how Canada became known as the last stop on the Underground Railroad for escaped slaves in the years to come.
In 1812, Richard Pierpoint, a freed slave and Loyalist who once fought with Butler's Rangers during the American Revolution, petitioned General Isaac Brock to form an all-black militia unit. He agreed and a small unit, a Company of Coloured Men (under a white officer) was formed. They served mostly in the Niagara theatre, where most of the fighting actually occurred in the war.
This 'Coloured Corps' fought in the Battle of Queenston Heights in 1812 and was noted as being influential in the British victory. They continued to fight for the British in 1813 at the Battle of Fort George. By 1814, they became an artificer unit tasked with building fortifications and blacksmith work. After the war, many received land grants in Niagara for their service to the Crown.