Final answer:
During World War I, the Army and Navy created the Nurse Corps, which formally admitted women into the U.S. military for the first time. This allowed women to serve with the designation of Yeoman (F), providing them military pay, benefits, and eventually, veteran status.
Step-by-step explanation:
The Army and Navy created the Nurse Corps during World War I, which formally admitted women into the U.S. military for the first time. Although women had previously worked for the military as civilians, it was during WWI that the Naval Reserve Act of 1916 led to the unprecedented enlistment of nearly 12,000 women in the US Navy and Marines with the designation of Yeoman (F), yielding them the status of military members.
This was a significant shift from earlier practices as it granted women military pay, benefits, and later, veteran status. The Navy Nurse Corps was established in 1908 and the Army Nurse Corps was established in 1901, but it was during WWI that their roles became more formally integrated with the armed forces.