Each year, more than half a million migrant children journey from countries around the globe and enter the United States with no lawful immigration status; many of them have no parent or legal guardian to provide care and custody. Yet little is known about their experiences in a nation that may simultaneously shelter children while initiating proceedings to deport them, nor about their safety or well-being if repatriated. Migrant Youth, Transnational Families, and the State examines the draconian immigration policies that detain unaccompanied migrant children and draws on U.S. historical, political, legal, and institutional practices to contextualize the lives of children and youth as they move through federal detention facilities, immigration and family courts, federal foster care programs, and their communities across the United States and Central America. Through interviews with children and their families, attorneys, social workers, policy-makers, law enforcement, and diplomats, anthropologist Lauren Heidbrink foregrounds the voices of migrant children and youth who must navigate the legal and emotional terrain of U.S. immigration policy. Cast as victims by humanitarian organizations and delinquents by law enforcement, these unauthorized minors challenge Western constructions of child dependence and family structure. Heidbrink illuminates the enduring effects of immigration enforcement on its young charges, their families, and the state, ultimately questioning whose interests drive decisions about the care and custody of migrant youth.