Despite early recognition of the importance of military institutions for understanding social organization and social change, sociology established no strong research tradition to study the military until after World War II. This paper explores the origins of this sub-field by focusing on the pioneering contributions of Morris Janowitz. Relying on a comprehensive review of primary source documents, it provides a history of the first twenty years of the Inter-University Seminar on Armed Forces and Society (IUS), an organization Janowitz founded in 1961 to support, extend, and routinize sociological study of the military as a social institution. Special attention is paid to the relation between the development of this institution and Janowitz's intellectual biography and to the strains resulting from the IUS's attempts to pursue multiple and sometimes conflicting goals.