This study traces the history of the national committee chairmanships of the two major political parties in the United States, emphasizing the national conventions and presidential campaigns – where national factions often reveal themselves. Candidate and ideolological factionalism, as the evidence of this volume demonstrates, has been the principal engine of convention action. Factional conflicts have had consequences not just for the political parties but for the party system itself. The institutional history of the two national committees and their chairmanships reveals a previously unrecorded aspect of United States national party development.