American women join the military
Women working in block mills during WW1.

WW1 was the first war women were inlisted in the armed forces. They never actually saw battles but they did work with the Navy doing clerical needs. The only reason the Navy actually let women join was because there was such a shortage of men they needed someone to do the work. The women wore standard uniforms during work. Most women did clerical jobs while others did jobs such as photographers, chemists, and pharmacists.
The army refused to enlist women, instead they hired them as temporary employees to do the clerical work. The only women who actually served in the army were the women in the Army Nursing Corps. Overall, by the end of the war an estimate of 11,000 women had served.