People like to call the U.S. a melting pot but we aren't nearly as melty as South America. I blame protestantism. They mainly didn't mix races. They just pushed the natives out. If you ask where all the natives are in North America you'd send people to a reservation or something.

In South America the Catholics just treated the natives like people, baptized them, married them, ordained them to the priesthood, made them governors and bishops. If you ask where the natives are, it is just everyone.

The few places with tons of intermarriage in North America are places like Quebec and New Orleans, places that were predominantly erm Catholic.