Answer:
The Native Americans.
Explanation:
They believed that the land belonged to anyone and everyone, belonged to great spirits and was given to them to use as needed.
Mexican immigrants is your answer.
Midwestern farmers traveling to Southwest America would be entering into Mexico (before the Mexican-American War), which included present-day Texas stretching to present-day California.
hope this helps
Generally speaking the Mormons treated the Native Americans with disdain as they moved and expanded, since the existence of the Natives conflicted with the story of creation that the Mormons held dear.