[Gunshot] [Horses neighing] Narrator: Black soldiers fight side-by-side with their British brothers-in-arms, but are segregated into their own unit: the Corps of Colonial Marines.

-Let's get into these.

-What've you got for me?

Russell Burke: I got you some maps.

Narrator: Nickerson and Dr.

Burke study a map to better understand what the soldiers would have experienced.

Graham Nickerson: So we're on this little island.

And if we were standing here in 1814 and we were looking out across the channel here and out to sea, we would have seen, like, the most powerful navy in the world, basically patrolling this area and dominating the Chesapeake.

Narrator: With the valuable manpower the Colonial Marines brought to the fight, the British launch raid after raid from Fort Albion across the Chesapeake.

Matthew Taylor: The Colonial Marines are local, so they're more likely to have a better feel for the ground and therefore guide the British Army more effectively.

Any encounters with civilian Americans shows that the British force is amenable and friendly to the enslaved, but not to the slave owners.

Narrator: In August 1814, the Colonial Marines advance with the British forces, first to Bladensburg, Maryland, and then straight on to Washington, D.C.

Taylor: And most famously, of course, the British Army burned down the White House.

It's impossible to imagine that operation taking place without formerly enslaved African Americans.

For an enslaved person to be part of an effort burning down the White House-- to burn down the symbol that represents their continued lack of legal rights is pretty symbolic for a lot of black people.