What about when Europeans ended worldwide slavery? What about the nations I mentioned that never used slaves?
By your definition, the only nations in history to be an ethnicity are "white nations" (Scandinavia, Switzerland, Austria, Germany) besides a few in Asia.
ALL of Africa had slaves or used slavery to profit, all of the arab world used slaves, all of the Indian world used slaves, Russia, China and the slavic lands used serfs which are basically slaves.
Yes, America used slaves but the slaves descendants are profiting way more now than if their ancestors hadn't been enslaved. Blacks should be thankful their ancestors were put to work here instead of in some Congolese jungle so they wouldn't rot there without their Yeezys and rap music. Infact, even if you were in African slave you would be better off in America than in your home region, because if you were up for auction it meant you got captured by a rival warlord, who would have enslaved you or straight up smashed your head in with a rock and eaten you.