In 1926, Jenness succeeded Canada's first Chief Anthropologist, Dr. Edward Sapir, as Chief of Anthropology at the National Museum of Canada, a position he retained until his retirement in 1948. During the intervening years, although hampered by the Great Depression and World War II, he sought to expand the National Museum's exhibits, anthropological collections, and reputation, as well as to improve the recognition, understanding, and living conditions of Canada's native peoples. In 1939 he became president of the American Anthropological Association.