Early education has emerged as a critical issue for state policymakers, who during the 2015-16 fiscal year alone invested nearly $7 billion in programs for our country's youngest learners. Support for preschool is broad and diverse, present in large and small states, in those densely and sparsely populated, and in states led by both Republicans and Democrats. Although there is considerable research on the elements of high-quality preschool and its many benefits, there is little information available to policymakers about how to convert their visions of good early education into on-the-ground reality. This report fills that gap by describing and analyzing how four states--Michigan, West Virginia, Washington, and North Carolina--have built high-quality early education systems. It is based on reviews of policy documents, studies, and data in each state, as well as observations of programs and interviews with 159 individuals, including policymakers, program administrators, providers, teachers, parents, advocates, and researchers. These states exemplify an array of promising practices that are designed to meet a state's needs and to satisfy its priorities. (author abstract)