Before World War II, most married women were housewives and stay-at-home moms. This meant that they were dependent on their husbands for money, food, and other resources. The few women who went to work tended to be of lower-class backgrounds and held domestic-type jobs that people considered "appropriate" for women, such as cleaning and clerk work with low pay. Many women lost their jobs during the Great Depression or gave them up to create opportunities for more men to work.
When the United States entered World War II after the bombing of Pearl Harbor, most American men were conscripted to fight in the military. This left no one to work in the factories and shipyards but they were still needed to produce weapons and supplies for the war effort. Companies and the American government started recruiting women to fill the jobs that in the past had been seen as only for men.
The Rosie the Riveter image and idea were used during the war by companies and the American government to encourage housewives to join the workforce.

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