The original concept of a non-Regular Army component, existing to augment the standing military, can trace its origins to the United States Volunteers. State volunteer forces were used extensively to augment the Regular Army throughout the 19th and early 20th century. During World War I and dictated by the provisions of the National Defense Act of 1916, states contributed men to the "Volunteer Army" (more commonly known as the National Army).* "The Draft Force of the United States Army", (Yarborough, William P., Lieutenant General, RA), Self Published, 1973 During World War I, a standard practice developed for Regular Army officers to serve in higher positions within the National Army, and thus hold two ranks - a permanent rank and a temporary rank. This concept was related to the idea of the brevet rank, which had generally fallen into disuse by the time of the First World War. The National Army was suspended after World War I.
