A new kind of professional social reformer sought to impact American society in a new way in the late 19th and early 20th centuries. Physical education professionals -trained in scientific theory, confident in the wide applicability of their expertise - adopted competitive team games as a means of molding the physical, moral, and social characteristics of young men and women. The invention of the game of basketball in 1891 was one of the first concrete manifestations of their outlook. Educators and reformers used basketball to teach children and young adults particular kinds of values on organized playgrounds, in high schools and colleges, and in institutions like the YMCA and settlement houses. They viewed it as a tool of social cohesion. Yet it often became something different: a highly competitive public spectacle, played in front of paying crowds by professionals and skilled amateurs, and not simply a tool for educators and social reformers. Studying the game's early history therefore illuminates a wide variety of the issues currently of interest to scholars of the Progressive era: the growth and spread of the ethos of professionalism, the tradeoff between individualism and social cohesion, the relationship of sport to contemporary conceptions of gender, and the relationship of sport and physical education to social reform. The development of basketball as both educational instrument and public spectacle illuminates the ways in which reformers and professionals designed an institution to suit their purposes - and how the targets of reform sometimes turned it to different purposes.