And a few other things you forgot to post.
During the time of Francis Scott Key over 90% of the earth had slavary.
A large portion of those were black owners.
As a matter of fact slave trade out of Africa would have been greatly restricted if not for the streamlining of black slave traders.
And just about every sub category of humankind has been enslaved at one time or another.
There are very few places on earth where the black man has prospered more then the USA.