"When recruits in the new Women's Army Auxiliary Corps - commonly dubbed WAACS - reported for training at Fort Des Moines, Iowa, women for the first time in American history became members of Uncle Sam's Army."
(The earned title "the first woman in the Uncle Sam's Army" is believed to go to a lass named Deborah Sampson, who served in George Washington's army in 1781, under the name "Robert Shurtliff".)
Another WAAC photo-essay can be seen here.