the racism of the star-spangled banner

[Retrograde]

6. Possibly

The notion that "slave" = "African" is a US invention: slavery has existed throughout human history, but the notion that people of a certain race are genetically inferior and destined to be slaves seems to come from the American South, and was vigorously reinforced after the cotton gin made cotton the big cash crop. "The Star Spangled Banner" was written early in that time, but we can see references to "slave" meaning someone with no autonomy in earlier pieces - "Rule, Britannia", for instance, claims that "Britons never never never shall be slaves"

I think the word is used for scansion, because it rhymes with grave, and because the author is trying to imply that the British troops are only fighting because they're commanded to - I don't think Black forces were even on his radar. It's still a pretty mediocre poem, and nigh impossible to sing.