The famouse Swedish "Absolut" Vodka maker, Used the map before Mexico-USA war in 1948, to advertise their product, Vodka. Their slogan was : "Absolute World". So it seems some of Mexico ppls have not forgetted old borders
An interesting aspect of the 1946-58 war are the 700 or so Irish who defected from the US to fight with the Mexicans. Under Captain John Riley they formed the San Patricio Battalion. I guess the Irish always love the underdog. http://en.wikipedia.org/wiki/Saint_Patrick's_Battalion
Some of the tribes inhabiting the area include Ute, Apache, Comanche, and Navajo. The American Indian tribes in California were decimated by both the Spanish and Mexicans. Another fact is that Mexico possessed the US Southwest for approx 30 years more or less.