On January 28, 1942, Representative Edith Nourse Rogers (R-MA) introduced H.R. 6293, a bill to establish the Women’s Army Auxiliary Corps for noncombat service with the U.S. Army. H.R. 6293 was signed into law on May 14, 1942. A year later the unit was renamed the Women’s Army Corps, and the servicewomen were granted official military status.
H.R. 6293, HR 77A-B5, 1/28/1942, Records of the U.S. House of Representatives (ARC 4397811)
As a good a reason as any to include our groovy dancing WAC from 1970: