It must be a nice consolation for the various European powers that their colonies breaking away seems to have absolved them of any blame not just the institutionalization of chattel slavery, but apparently also the creation of scientific racism.

Yes, it was - same as I suppose it is a great inconvenience to you that the Brits were calling for the abolishing of slavery long before the Civil War.

That said, sure, scientific Racism was project of Western Civilization, but it seems really that America - at least where Black people were the subject (and maybe also Indians, but they were more to be exterminated - not enslaved) - put a lot more heart and soul into it than other participants.