I think the important comparison there, and something I often keep in mind, is that the US is a lot more diverse racially, even with its segregation, than a lot

I think the important comparison there, and something I often keep in mind, is that the US is a lot more diverse racially, even with its segregation, than a lot of other countries in the world. It's a lot easier for a country that's 90% the same race to not have open and prevalent racial issues, since there will be entire cities/areas where you won't even meet someone of a different race. It's easier to be morally upstanding about you presume you and your fellow citizens would handle a potentially racist situation when it's hypothetical and not just a fact of life. None of this is meant to excuse any of the awful stuff in the US, but to point out that there's a lot of confounding factors. It was a lot easier for Europe to take the high ground on abolishing slavery early on when they were century old empires who could still fill their coffers by exploiting people in Asia and Africa directly instead of importing them.