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.
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.