Using an original and unique database of state charter school laws that we have developed, we analyze how state policymakers have incorporated two key values into state charter school laws: flexibility and accountability. We supplement this database with other state-level measures to answer two specific questions: What factors influence the degree of flexibility and accountability in state charter school laws? How does the content of state charter school laws, and the different values those laws embrace, affect the formation of charter schools in the United States? Overall, we show that state political and contextual factors help account for the degree of flexibility, but not accountability, in state charter school laws. Further, we show that the degree of flexibility, accountability, and political and contextual factors influence the number of charter schools that form in the states.