A key spokesman for the medical establishment against the antivivisection movement, Walter B. Cannon was head of the Council for the Defence of Medical Research of the American Medical Association from 1908 to 1936. He and his colleague William W. Keen monitored antivivisectionist activity, mobilized the medical profession, lobbied politicians, testified in public hearings, and wrote tirelessly in defense of animal experimentation. Cannon was George Higginson Professor of Physiology at Harvard Medical School and head of its physiology department. Keen was a prominent surgeon and neurologist from Philadelphia. The Cannon Papers consist of over 1.5 linear feet of correspondence, 1905-1928, primarily between Cannon (1871-1945) and Keen (1837-1932) regarding their mutual opposition to the antivivisection movement.