Fifteen years after the first public charter school opened in St. Paul, Minn., charter schools remain a powerful educational innovation. Charter schooling expands choices for students within the public system and provides more customized teaching and learning opportunities for teachers and students by allowing for greater variation in the kinds of schools that are available. At the same time, charter schools maintain core public education ideals, such as providing universal access for students and public oversight and accountability. This report from Education Sector provides insight into how states can teach other states about charter schooling and laws.