I only mentioned black/white marriages.

According to this 2015 data, 17% of new marriages in the US were interracial and only 11% of those were between a black person and a white person. So less than two percent of new marriages were between a black person and a white person. That is rare.

The black population, which is mostly made up of people whose ancestors have been here for centuries, was shown to be intermarrying at a significantly lower rate than asian and hispanic people, most of whose ancestors would have immigrated much more recently. There is still very obviously a big racial divide.