Mexicans are "Americans"? Really> And I'm the stoopid guy?
Here's the atlas you're in need of:
I know it's difficult living in Santa Cruz and not having any contact with the real world. Take a nice little drive down to SD or Yuma or Tucson. It's a long way away. In between, there's some vestige of the United States of America in between. Funny how you seem to not get that.
Foam at the mouth all ya want, thems the facts.
The first map to use the name America, in 1507, applied it to Brazil, so maybe the only real Americans are Brazilians.
The Aztecs or Mexica were immigrants from the north--their language, Nahautl, is related to a number of Indian languages of the US Southwest including Ute and Comanche. So it's no surprise that DNA evidence would confirm migration from north to south.