User blog comment:Callumthered/Mexico beats America?/@comment-32656-20120206091304/@comment-32656-20120207022158

Honestly, that was only the case in Texas, Fed. All of the settlers that were elsewhere went there without permission.

They really couldn't have blocked them, either - the areas in question were more or less uninhabited, and Mexican colonists were moving elsewhere, closer to home. Nor was there any real problems for the Mexicans to move up there - they just didn't. Also, the Mexicans were only really starting to move into Baja in any real numbers at this time, too.