My own theory is racism. Other countries in the Americas are not obsessed with ancestry. But bigotry against Scots, Irish, Italians, Africans, Chinese, Polish, etc. ran / run rampant.

Jeez, are there people the English didn’t hate? I wonder if the overall disdain for other people the English had in the 1800s wasn’t what was carried over to the new world and festered into this.