This paper considers the mental health consequences of internal migration within the United States on Mexican-origin immigrants and migrants. Mexican-origin immigration, and transnational and migratory movements into the U.S. and within the United States have a long, cyclical history that is associated with employment opportunities, particularly in the agricultural industry. Although the immigrant and migrant experience can be enormously stressful, the mental health consequences have very limitedly been studied. Although it might be expected to find higher rates of mental health problems and disorders in the migrant and immigrant populations, the opposite seems to be the case based on a large, well-controlled study using a highly respected, reliable, and valid cross-cultural measure of mental health — namely the Composite International Diagnostic Inventory (CIDI). What is of concern is that mental health problems in immigrants and settled-out migrants seem to increase along with increased residency in the U.S. The immigrant and migrant may be attracted to come to the U.S. to work and improve his/her educational status and standard of living in accordance with the “American Dream,” but the long-term effects of that decision may prove to have, at least for some, an enormously stressful and detrimental impact.