In my opinion, there is a lot of misinformation, some of it just plain silly, being spouted in this thread.
There are no people on Earth living on land that their group evolved from. Everybody's ancestors took land from somebody else going back as far as written history reaches and no doubt before then too. Had Santa Ana been a decent sort and benevolent dictator, the Texicans would have lived out their lives peacefully as Mexican citizens. But his excessive taxation and oppressive dictates became too much for the freedom loving Texans and eventually they revolted as people are wont to do when pushed far enough. Check your history books. It has happened time and time again all across the globe. At such time as the U.S. government devolves into an oppressive totalitarian regime, there will likely be another revolution here. And then will you brand the victors the bad guys?
Sometimes the revolutionary victors have made things much better. At times they've made them worse.
If you are going to fault those who took the land from Mexico, would you not also have to fault those who took the land from England? Again, if the Britsh had not been oppressive masters, the colonists would have lived out their lives as loyal British subjects.
In the Indian Wars, yes the Spaniards and other 'white men' did injustice to the Indians, but in the honest historical accounts, the Indians did some injustice of their own, both to the 'intruders' and to other Indians. There really are few innocent victims to be found in the broader truths of world history if you go by who deserves to have the land and who doesn't.
Only the most narrow minded ideologues demand that villains and victims be assigned in all aspects of history.