Numerous theories have been proposed as to their motives for desertion, including cultural alienation, mistreatment of immigrant soldiers by nativist soldiers and senior officers, brutal military discipline and dislike of service in the U.S. military, being forced to attend Protestant church services and being unable to practice their Catholic religion freely as well as religious ideological convictions, the incentive of higher wages and land grants starting at 320 acres offered by Mexico, and viewing the U.S. invasion of Mexico as unjust.