Black women were accepted into WAAC from its beginning in the summer of 1942. About 80 percent of the black women accepted for officer training had attended college and had been working as teachers or in offices. While they were in training, black officer-candidates attended classes with white candidates and ate meals with them, too. However, almost all social activities were strictly segregated; for example, the army set up separate service clubs and beauty shops for blacks and whites. At graduation blacks were assigned to all-black auxiliary units. A black women's unit did not deploy overseas until February 1945. The 6888th Central Postal Battalion, commanded by Major (later Lieutenant Colonel) Charity Adams (1918–2002), first went to England and then settled in Paris, France. Working around the clock in three shifts and seven days a week, the eight hundred black women in the battalion were responsible for getting mail to all members of the U.S. military in Europe. Military personnel assigned to Europe moved constantly, so the battalion had to keep an address update card for each one.

Black women were not admitted into the U.S. Navy WAVES or the Coast Guard SPAR until November 1944. By July 1945 there were seventy-two black enlisted women and two black officers in the WAVES. Four black women had been accepted by SPAR. Black women were never accepted into the Marine Corps Women's Reserve or the Women's Airforce Service Pilots (WASP).