The organizational field encompassing North American major league professional sport changed dramatically over the last quarter century despite the constraining forces associated with this level. Given this, the purpose of this article was to explore the evolution of one organizational field over an extended time period in order to enhance our understanding of the multifaceted nature of its change. Four dimensions of this field were considered for study: communities of actors, their exchange processes, their governance structures, and their beliefs and institutional logics of action. These dimensions were operationalized to provide evidence of the evolution of the organizational field. Data were collected from personal interviews with league and franchise leaders, from documents retrieved from the leagues and Halls of Fame, and from a selection of historical books. The results of this research show increased interaction among the actors in the field, a growing awareness that they were engaged in a common enterprise, and the erosion of the coexisting logics of action prevalent in the field in the early 1970s.