History between black and white people in this country has a lot to do with people attitudes. I know a lot of black people who can have white friend but a white male marrying their daughter is a bit too much for them. They don't want white in laws or half white kids in their families.
Yes, just as scotsmen immigrants didn't want their blood mixing with english immigrants blood many years ago. But their ignorant ways have died off. Sure, there may be one or two families up north who would rather their daughters marry their cousins than a different race like a german, but you will always have ignorant people in every culture.