This chapter provides context for Clarence Samuel Stein's engagement with and translation of Ebenezer Howard's proposed Garden City and for his advocacy of these ideas in his projects, service, writings, lectures, and consulting activities throughout his career. Stein promoted Garden City as an “ideal system” for neighborhood preservation, housing reform, traffic congestion mitigation, and park design. What struck Stein about the Garden City—rechristened Regional City—was its spirit of cooperation and community, the balance between open spaces and development, and the notion that distinctive planned new towns served as the building blocks of the region. This chapter reviews the Garden City concept with a focus on its adoption and evolution in the United States during the first half of the twentieth century. It also considers the initiatives of the Regional Planning Association of America (RPAA), where Stein served as founder and informal sponsor, including the Radburn Idea.