United States Army Reserve
The United States Army Reserve is the reserve force of the United States Army. People in the reserve forces are not full-time soldiers, they also have a civilian career. The reserve forces of the US Army are made of the US Army reserve and the Army National Guard.
The Army Reserve was formed in 1908 to provide a reserve of medical officers to the Army. After the First World War Congress reorganized the U.S. land forces. The National Defence Act of 4 June 1920 authorized a Regular Army, a National Guard, and an Organized Reserve (Officers Reserve Corps and Enlisted Reserve Corps) of unrestricted size. The Organized Reserve later became the Army Reserve.