In addition to this, it is important to remember that
laws encouraging discrimination against black people continued to exist in many parts of the country until
very recently. This still has an effect in American culture.
I'd also like to add how fucked up many people's perception of race is in many partss of . White people from places other than Northern EU or NA are often considered be "impure" or "not fully white," to the point where "Hispanic" is a separate option in census and polls, regardless of the person's actual ethnicity (so a German-Chilean, an "indio" Mexican, and an Afro-Dominican would all fall under the same category). This stems from all the way back to before the Civil War, when the rich plantation owners spread racist propaganda to ensure anyone who wasn't an educated Anglo-Saxon would remain in the lower end of the social spectrum (which is where bullshit myths like "THE BLACK IRISH" and "THE MOORS WERE NIGGERS" come from).
What's fucked up is that these ideas remain widely accepted among the general public. There is a gigantic stigma to racial mixing outside of large liberal cities like NYC or LA, to the point where most neighborhoods are racially homogeneous. You've even got people who cast their vote based solely on the race of the politicians.... many people voted against Obama just because of his black ancestry, and many voted for him for that same reason.