The point I was making is that we all of us have lots of ancestors, and they don't all necessarily come from the same part of the world.

In fact they almost certainly don't all come from the same part of the world if you go back more than a couple of generations. It's probably true that most people in England have ancestors from Africa, dating back to the 18th century.

I'm not in any way suggesting that people shouldn't take pride in their ancestors who came from Africa, just pointing out that the label "American of African descent" includes large numbers of people who aren't black, and that there are lots of black people in the United States who aren't in fact Americans of African descent.