Intended to contribute to a better understanding of research library development in the United States, this report describes the history of the development of the library of the State Historical Society of Wisconsin from 1904 to 1918. It is based on records of the relationships between three principals--John R. Commons and Richard T. Ely (members of the University of Wisconsin faculty) and Reuben Gold Thwaites (superintendent of the Society)--and their associates and subordinates at the two institutions. From a rich mixture of personal ambitions, institutional and personal interactions, variant perceptions of the functions of libraries, and other factors, the library of the Society was developed during the period 1904 to 1913 into--among other things--a major center for the study of the trade union movement in the United States. The development of the library resulted from the working of a complex collecting effort by an agency--the American Bureau of Industrial Research--connected administratively to neither the Society nor the University. Afterward, the Society continued the collecting program begun by the Bureau, but in a substantial degree of dissociation from the conditions that led to the library's earlier development. The author's vita and numerous references are included in this report. (Author/ESR)