 This chapter provides a brief account of the important changes in the structure and function of U.S. medicine as a result of the World War II. It begins by identifying key interactions between the leading urban academic health centers and their low-income neighbors. It then discusses the changes to the health care system brought about by the participation of the United States in World War II. These include the GI Bill, private health insurance, biomedical research, and the passage of the Hill-Burton Act.