This article consists of a case study and policy analysis of a conflict between two federal mandates that arose during the initial implementation of the No Child Left Behind Act in 2002 in a southern school system, Richmond County, Georgia. The first part of the article documents the conflict, drawing on primary source documents and interviews with the school superintendent and school board attorney. A U.S. District court judge ruled that the 1972 court order that had mandated county-wide school desegregation was in conflict with No Child Left Behind's public school transfer policy and granted the county a one-year delay so that the school system could study the policy's likely effects. The U.S. Department of Education's response to the judge's ruling instigated a situation that led to a federal-local political disagreement, whose origins and resolution are described. In the article's second section, the author places these events into broader historical perspective, arguing that they reveal how federal policy in elementary and secondary education has shifted during the intervening decades since the Elementary and Secondary Education Act's enactment in 1965. The case highlights the changing federal-district relationship, the equitable implementation of the No Child Left Behind public school choice provision, and the nature of federal authority in education policy, and how it is currently being exercised by the Bush administration.