From 2011 to 2016, about 179,000 unaccompanied children from El Salvador, Honduras, and Guatemala were apprehended entering the United States. While the crisis received ample media attention, limited data has meant little rigorous analysis of what made those children move. Using unprecedented data on each apprehension, we measure how violence in these children’s hometowns shaped their migration. In the average municipality the children came from, 10 additional homicides caused about six additional apprehensions. This implies that additional cost-effective investment in regional violence prevention during this period could have substantially reduced the suffering and costs associated with unaccompanied child migration, and suggests unexplored opportunities for US foreign policy to complement US immigration policy goals.