> But I'm confident that 99% of white Americans have spoken to a black person.

I'm no more confident of that than in the 90% haven't made up statistic that this was offered in response to.

The truth is probably somewhere in between (and may be closer to the 90% haven't side, especially if, as suggested in another comment, one excludes the minimal interactions around things like retail commercial transactions and the like, and only includes substantive conversations.)

> Except for a few states like Vermont, most states and most cities have significant black populations.

That doesn't mean that the black population interacts with the White population all that much.