>>Different ethnicities would self segregate aside from trade and sometimes labor. Congratulations, you just restated the OP. Dutch, English, French are subsets of Caucasian. They banded together in the face of Indian attacks unless there was outside political pressure, which is why the American nation (ethnicity) formed out of them. Whites have more in common with each other than they do with non-whites. Arguing otherwise is like claiming there's no such thing as black, because they all came from different tribes and spoke different languages.