The 366th Infantry Regiment was an all African American (segregated) unit of the United States Army that served in both World War I and World War II. In the latter war, the unit was exceptional for having all black officers as well as troops. The U.S. military did not desegregate until after World War II. During the war, for most of the segregated units, all field grade (majors and above) and most of the company grade officers (second lieutenants, first lieutenants, and captains) were white.