The first time American women fought in a war was during the American Civil War. Women were not allowed to be selected into the draft, so they disguised themselves as men and fought instead. A few of them were only discovered to be women when found dead.
American women were only allowed to serve in the army during the First World War. Many of the women were nurses and staff who cooked and catered for injured soldiers. But many of these women were white as at the time slavery and racism prevented black women from giving their services to America.