What political conflicts were triggered by u. s acquisition of lands in the u. s. mexican war?

It mostly about the citizenship of mexican people where the land is acquired.

At that time, united states wanted Mexican citizens in the acquired land to became a part of American citizens and counted as their workforce. Mexican government believe that they are still Mexican citizens regardless of the ownership of the land. This political conflict lead to the U.S. Mexican war

to stay where they were until m sent for