Thesis: The US labor force changed greatly toward a job market mostly made of women during the second world war, but then greatly changed back to a male-dominated labor force just shortly after the second world war.
At the start of World War II, women made on like a quarter of the workforce, as most had to stay home to continue tending their children and maintaining their home. Even though many people kept from having children because of the Great Depression not just recently passing, and many people still couldn't afford maintaining a family, many women still stayed at home instead of signing up in the war because they felt that was the way things should be.