Let’s take the national anthem literally, and the songwriter at his word

And where is that band who so vauntingly swore,
That the havoc of war and the battle’s confusion
A home and a Country should leave us no more?
Their blood has wash’d out their foul footstep’s pollution.
No refuge could save the hireling and slave
From the terror of flight or the gloom of the grave,
And the star-spangled banner in triumph doth wave
O’er the land of the free and the home of the brave.

The War of 1812 was caused, among other things, by Great Britain’s attempt to restrict U.S. trade and America’s desire to expand its northern territory by annexing Canada. By 1810, more than 15 percent of the U.S. population was enslaved, and British forces recruited escaped slaves to fight for the slaves’ freedom against the American militia. This unit, referred to as the Colonial Marines, was part of the British forces that overran Washington, D.C., in 1814 and set fire to the White House.

So when Key references the “foul footstep’s” of the “hireling and slave” who “no refuge could save” from “the gloom of the grave” in the third verse, he’s referring to the killing of Colonial Marines. As noted by The Root political editor Jason Johnson, “The Star-Spangled Banner is as much a patriotic song as it is a diss track to black people who had the audacity to fight for their freedom.”

Following the War of 1812, the Treaty of Ghent was signed, with the United States ordering the return of “such slaves as may be in your control, belonging to any inhabitant or citizen of the United States.” The British refused.

via The Undefeated Let’s take the national anthem literally, and the songwriter at his word