AHC: From a 1660 PoD end the racial caste system in North America by 1800, but make society dystopic by 1890

Alright, here's the challenge, bring an early end and favorable resolution to one of the REALLY BIG PROBLEMS of North American history bedeviling it through the present, the racial caste system. No PoDs before 1660 so that the system of African slavery in America already has some momentum to overcome and I believe the doctrine of partus was established in some colonies. But get slavery and racial discrimination problems solved by 1800. Without adding or intensifying any genocides to history in North America, or any other continent (Europe, Africa) that did not happen in OTL.

But then, for this alternate America, that lacks racial inequality or caste as a political fissure, point of contention, organizing principle, embarrassment, or hangup, imagine some worse sociopolitical or cultural development that is embedded in North American society by no later than 1890 that would make most of us consider the situation dystopic.
You'd probably need something incredibly radical to bring about true racial caste, like a new Christian movement that holds all Christians are equal no matter their race. Obviously that movement will have other tenets and doctrine, and perhaps we can imagine this movement is quite radical and demands a theocratic organisation of society where no politics is conducted without the consent of the clergy. Perhaps it's also an expansionistic movement to the point of literally crusading against the evils in the world, one of which it believes is racism but also false doctrines like Catholicism meaning a justification for imperialism. Maybe since slavery is condoned in the New Testament, it doesn't have a problem with slavery as long as the Bible's laws regarding it are followed, meaning the proposal of some radical proslavery advocates like George Fitzhugh that slavery should include lower class whites is permitted, hence the poor can sell themselves into slavery. Maybe it has Biblical punishments for all manner of crimes ranging from flogging to stoning people for adultery, blasphemy, apostasy, or homosexuality to even burning alive, strangling, or beheading for various other crimes (see Leviticus and Deuteronomy).

So most of North America is a theocratic dictatorship (nominally democratic of course, but you can only vote for candidates the church likes) with legalised slavery that oppresses Catholics, any denomination that isn't the main church/tolerated by the main church, and all non-Christian religions and has a draconian judicial code aimed at enforcing social mores that even for the 19th century are backwards by the standards of Europe.