The U.S. military was still heavily segregated in World War II. The Army Air Corps (forerunner of the Air Force) and the Marines had no blacks enlisted in their ranks. There were blacks in the Navy Seabees. The army had only five African-American officers. In addition, no African American would receive the Medal of Honor during the war, and their tasks in the war were largely reserved to non-combat units. Black soldiers had to sometimes give up their seats in trains to the Nazi prisoners of war. World War II saw the first black military pilots in the U.S., the Tuskegee Airmen, 99th Fighter Squadron, and also saw the segregated 183rd Engineer Combat Battalion participate in the liberation of Jewish survivors at Buchenwald. Despite the institutional policy of racially segregated training for enlisted members and in tactical units; Army policy dictated that black and white soldiers would train together in officer candidate schools (beginning in 1942). Thus, the Officer Candidate School became the Army's first formal experiment with integration- with all Officer Candidates, regardless of race, living and training together.