Because the Immigration Act of 1924 specifically excluded Asian immigration, the United States turned to Mexico as its primary source of cheap labor during the late 1920’s. With its proximity to the United States, Mexico supplied thousands of both legal and undocumented workers to labor on farms and ranches and in construction and mining in the Midwest and Southwest. These immigrants joined Mexican Americans, some of whom were descendants of Mexicans who had entered the United States following the MexicanWar of 1846-1848. At the time of the Depression, several hundred thousand people of Mexican ancestry were living in the United States.

Rampant job losses caused by the Depression generated anti-Mexican sentiment, which had grown following World War I and had since redoubled with the massive number of Mexicans who immigrated during the mid-1920’s. As the Depression deepened, government authorities determined that the expense would be less to return Mexicans to Mexico than to keep them on the welfare program.

With the cooperation of the Mexican government, the United States repatriated about one-half million Mexicans between 1929 and 1935. Some of the people sent back to Mexico were actually U.S. citizens with long-established residences and others who were tricked or forced to go. Indicative of their historical pattern of immigration and deportation, Mexicans were welcomed back to the United States a decade later, when they were invited to fill the gaps in the American workforce as the United States mobilized for World War II.