In LIFE’s own words:
The idea behind the Women’s Army Auxiliary Corps is simply this: Women can do some of the jobs that men are doing in the Army. By taking over these jobs, they can release men for active or combat duty. For instance, if too many service troops are ordered away from a post, the post commander will send in a call for some WAACs. Pretty soon a WAAC contingent — probably a company — will descend on him and then disperse about the camp to do clerical work, mess work, light transportation work, mechanics work or any kind of work which women can do as well as men.