From the introduction of the "Gallinger-DC" bill in 1896 to the passage of the Laboratory Animal Welfare Act in 1966, organized medicine and the American physician have been active in promoting the humane and appropriate use of research animals and explaining to the public and legislators the importance of research using animals to medical progress. The role of organized medicine and science in events leading to passage of federal legislation is discussed. Past efforts of the American Medical Association and the American physician have been critical in numerous successful efforts at the local, state, and national level to prevent the passage of laws which restricted animal use for health research and impeded medical progress. This article demonstrates that current initiatives by physicians to preserve biomedical research are a reaffirmation of their traditional role.