OBJECTIVE: Centralized exchanges of scientific materials existed by the late nineteenth century, but they did not include medical publications. North American medical leaders therefore formed an association of institutions to run their own exchange: the Medical Library Association (MLA). After providing background to the exchange concept and the importance of institutional members for MLA, this article examines archival MLA correspondence to consider the role of its Exchange in the association's professional development before the 1950s.RESULTS: MLA's membership policy admitted only libraries open to the medical profession with a large number of volumes. But the correspondence of the MLA Executive Committee reveals that the committee constantly adjusted the definition of library membership: personal, public, sectarian, commercial, allied science, and the then-termed "colored" medical school libraries all were denied membership.CONCLUSION: Study of these decisions, using commercial and sectarian libraries as a focus, uncovers the primary justification for membership exclusions: a goal of operating a scientific exchange. Also, it shows that in this way, MLA shadowed policies and actions of the American Medical Association. Finally, the study suggests that the medical profession enforced its policies of exclusion through MLA, despite a proclaimed altruistic sharing of medical literature.
American Medical Association Drug Industry