The National Defense Act of 1916
Established, by statute, the Army of the United States as, "the Regular Army, the Volunteer Army, the Officer's Reserve Corps, the Enlisted Reserve Corps, the National Guard while in service of the United States, and such other land forces as are now or may hereafter be authorized by law".
The following year, in 1917, the Medical Reserve Corps, which was the initial Reserve organization, merged with the Officer’s Reserve Corp. By 1920, an amendment to the National Defense Act of 1916, further defined and streamlined the Army, “Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That the Army of the United States shall consist of the Regular Army, the National Guard while in the service of the United States, and the Organized Reserves, including the Officers’ Reserve Corps and the Enlisted Reserve Corps”. The Organized Reserves was interchangeably called the Organized Reserve Corps from 1920 until 1952 when the organization changed once again.
During the Korean Conflict, Congress began making significant changes in the structure and role of the Organized Reserves, resulting in the Armed Forces Reserve Act of 1952, and the transformation of the Organized Reserves to the United States Army Reserve (USAR). The Officer's Reserve Corps and the Enlisted Reserve Corps were legally eliminated, redefining the U.S. Army Reserve as the Ready Reserve, Standby Reserve, and the Retired Reserve.
As the Army Reserve became progressively more involved in combat support and combat service support, it wasn't long before Congress established the Office of the Chief, Army Reserve (OCAR) within the Army Staff, which was also to give Army Reserve Soldiers a voice on their behalf. Eventually, the United States Army Reserve Command (USARC) was created in October 1990.
As the U.S. Army Reserve developed, so did it's symbols!