The National Guard of the United States, part of the reserve components of the United States Armed Forces, is a reserve military force, composed of National Guard military members or units of each state and the territories of Guam, of the Virgin Islands, and of Puerto Rico, as well as of the District of Columbia, for a total of 54 separate organizations.
It was mentioned in White House Down.
All members of the National Guard of the United States are also members of the militia of the United States as defined by 10 U.S.C. § 311. The majority of National Guard soldiers and airmen hold a civilian job full-time while serving part-time as a National Guard member. These part-time guardsmen are augmented by a full-time cadre of Active Guard & Reserve (AGR) personnel in both the Army National Guard and Air National Guard, plus Army Reserve Technicians in the Army National Guard and Air Reserve Technicians (ART) in the Air National Guard.
The National Guard is a joint activity of the United States Department of Defense (DoD) composed of reserve components of the United States Army and the United States Air Force: the Army National Guard of the United States and the Air National Guard of the United States respectively.