The Army of the United States is one of the four major service components of the United States Army (the others being the Regular Army, the United States Army Reserve and the Army National Guard of the United States), but it has been inactive since the suspension of the draft in 1973 and the U.S. military's transition to a volunteer force. Personnel serving in the United States Army during a major national emergency or armed conflict (either voluntarily or involuntarily) were enlisted into the Army of the United States, without specifying service in a component. It also includes the "Retired Reserve". Those are retired soldiers that have reached the required years of creditable service, or creditable service and age; regardless of the component, or components they formerly served in.