This project will examine the late-twentieth-century history of illegal border crossing, Mexican migrant communities, and bi-national efforts to regulate the border. Employing a transnational lens, I investigate how Mexican migrants, Chicana/o organizations, nativist lobbies, and U.S. and Mexican officials reshaped national belonging during a critical period in North American history. That era, framed by the Bracero Program’s conclusion in 1965 and the passage of the Immigration Reform and Control Act (IRCA) in 1986, saw an unprecedented surge in circular, undocumented migration and key shifts in government responses. At the outset, I argue, Mexican officials discouraged emigration, but by the 1970s, those same officials were encouraging such departures as a solution to high unemployment and population growth. Simultaneously, the U.S. government attempted to address these same problems by militarizing the border more aggressively. Thousands of Mexican nationals found themselves without the substantive right to belong to either nation-state. In the context of those policies, migrants affirmed their own cartographies of belonging. Many young men living in the United States formed Mexican hometown associations that sent money across the border, making themselves central players in regional and national politics. For their part, elderly Mexican men, along with women and queer men, commonly responded to dominant gender and sexual ideologies by remaining in Mexico and depending on foreign remittances to survive.