.even if the states in question actually where taken from Mexico in the first place
Finally, on February 2, 1848, at Villa Guadalupe Hidalgo, north of Mexico City, American and Mexican commissioners signed a treaty to establish peace between the two countries.
According to the terms, Mexico recognized the Rio Grande as the boundary between the United States and Mexico. It ceded the territories of New Mexico and California to the United States, and in turn, the United States agreed to pay $15 million dollars and forgive Mexico's debts.
Then there's the: Gadsden Purchase Treaty : December 30, 1853
You have made it clear that you care nothing about the laws of the land, and rewriting history is WAY beyond your abilities.
However, you are welcome to tell it all to La Raza.