C.-E. A. Winslow was the leading theoretician of the American public health movement during the entire first half of the twentieth century. An eminent bacteriologist, he subsequently made outstanding scientific contributions to occupational health and to the hygiene of housing. As activist, theoretician and historian, he played an important role in environmental health, epidemiology and disease prevention, public health administrative practice, health education, public health nursing, mental health, medical care, and the improvement of living standards. When he died in 1957, the American Journal of Public Health commented that "For a long half century Professor Winslow could be found always at the thick of the struggle for the people's health. In whatever area new gains appeared possible of achievement, there he would be--planning, inspiring, leading, or digging in to hold the advance."