I agree, but it would have been a better idea to include graphs with and without the estimates. Since the only note on it is just a text note, it will be all too easy for people to think this is a full picture.

Slavery and illegal immigration are both big parts of how the U.S. population came to be, like it or not, and they are such big parts that, although I sympathize with the difficulties of estimating them, not estimating them seems like a bigger problem.

But, it's a cool article nonetheless.