In this report, we explain the work that has taken place over the last decade in Boston to not only improve K1, but to build on the successes of K1 through reform of classroom environments, instructional practices, and curricula in K1, kindergarten (known as K2 in BPS), and, more recently, in first and second grade. It is a story of reforming from the bottom up, of realizing that the work of increasing student achievement is not confined to a single grade, but requires sustained efforts to improve the grades that follow, efforts that persist despite multiple changes in district leadership. It is a story of the importance of using research and data to drive continuous improvement. It is a story worthy of attention from all states and districts across the country working to build on the gains made as a result of high-quality pre-K programs. It is a story that begins with the goal of universal pre-K. (author abstract)