[LS]

Unfortunately, if you look at the sidebar in my book, most demographic historians and demographers don’ t make that distinction. Could be one that I missed. Most of them in their “North American” estimates include modern day Mexico.

[driftless2]

Mexico and the Aztecs had cities with stone buildings, infrastructure, cultivation of large amounts of land, etc. Those are the hallmarks of large populations. Nothing like that existed north of the Rio Grande. Some historians, whose names I can't recall, for obvious political reasons try to dramatically increase the numbers north of the Rio Grande.

I had a sociology prof. in college who was a hysterical (he thought the Bush I admin was trying to murder the Indians) advocate of immense Indian populations in the area of the present U.S. His "specialty" was/is N. American Indians, and he occasionally gets his articles printed in the local rag. He never presented any proof, and I've never seen any proof that Indian populations were any more than 2-3 million. No big cities, no huge stationary populations, no remains of millions of people.