Charter schools are publicly funded schools that choose their students by lottery, and in most states, exist to serve the poor. They resemble independent schools in that they operate independently from bureaucratic constraints imposed by districts and are free to innovate as long as they have high achievement results. In a span of 25 years, charter schools have grown from one school in Minnesota to 6800 schools in 43 states, serving 3 million children. The book focuses on the most successful charter schools (the top 20 percent) that are closing the achievement gap and guiding students from kindergarten through college. The founders of these schools scoured the country to learn best practices from public, private, and parochial schools. Supported by generous funders who saw charter schools as the best hope for improving public education, they were able to replicate their successful models, evolving into Charter Management Organizations (CMOs) that oversee a network of schools. School operators then shared their findings widely through publications and workshops. The successful CMOs collaborate closely to offer professional development, and they even formed a graduate school of education to train teachers. While independent schools have never operated as a movement, with a sector mission, this book shows one way that independent schools might help each other to survive and thrive. It is worth noting, too, that a number of the leading charter school founders of the most successful schools described in this book either attended independent schools themselves or worked in independent schools prior to entering the charter movement.