Answer:
During the US Mexico war in the late 1800s, It was the Mexican Americans who were allowed to settle in the South West region of the US. And they left Mexico.
Step-by-step explanation:
After the war Mexican Americans decided to migrate to the US, and the US government allowed them to settle in the South West region. However, they still are fighting for their rights like right for education, etc, and they are still being considered as a second class.