***Mexican just want to take back what we stole from them in our imperialistic days.***
Lesson time! Obviously you slept in class.
Texas fought and won their war with Mexico. At the same time, problems between the US and Britain and Canada escalated over the Oregon territories.
Great Britain recognized Texas as a nation with the Rio Grand as the south border. Britain then tried to forge an alliance between Texas, Mexico joining with Canada against the US.
Texas was horrified at the thought and immediately opted to join the US. This caused another short war with Mexico in which Adrian Wool recaptured San Antonio for Mexico for a short while.
The US accepted Texas as a state and realized the whole back door was open to invasion. The US rushed troops to the tip of Texas where the Mexicans then began to bombard the fort named for the first US soldier killed there, FT BROWN.
The US then declares war on Mexico since they were bombarding a US army post in Texas and the rest is almost history. Upon signing peace papers, the US gave the government of Mexico MILLIONS IN GOLD to give up all rights north of the Rio Grande and Salt rivers. To my knowledge, this is something that has never happened before. You took land and kept it by force of arms.
Mexico accepted.
Then the US found it needed more land for their stagecoach line to California, so went, hat in hand, and offered Mexico even more gold for the Gadsden Purchase. Again Mexico gave up all territorial claims north of there.
That is why the official maps of Mexico show the northern border as they are today. The Government of Mexico has kept that treaty, only some cranks try to claim the land was stolen.
Meanwhile, war with Great Britain and Canada was avoided but there were other problems in the Oregon Territories beyond this scope which led to the Whitman massacre.
Isn’t history grand!
I was being facetious. I am a native Texan well versed in her history.