Living and working conditions in Mexican migration environments in the United States and Mexico have become increasingly insecure for migrants and their families and communities since the mid-1990s. The enactment of national, state, and local policies in the United States to restrict unauthorized migrants and the emergence of organized criminal violence in Mexico have contributed to this development. After large-scale unauthorized immigration from Mexico surged in the 1970s, the biggest threats Mexican migrants faced until the mid-1990s were mainly apprehensions for illegal entry followed by “voluntary departures” back to the Mexican side of the border or an occasional workplace raid, which interrupted a migrant’s employment for several days. Large-scale Border Patrol operations between the mid-1940s and 1954 repatriated large numbers of Mexican migrants, but more than two decades later, in the 1970s and 1980s, studies of Mexican migrants in the United States did not depict deportations, or the fear of deportations, as having major or broad effects in Mexican migration environments.