“America did do the Negro peoples dirty.”
Yes. But America, in my estimation, has made up for it.
Whole populations have been enslaved all throughout history, and never had that kind of ending.
It was basically the British who ended slavery. Their law was, if a ship, of any nation, containing slaves were found on the open seas, the ship was confiscated and the captain and crew were immediately hanged. That eradicated the slave trade.
The British could not end slavery from the stock of Negros in the USA.