National Guard (United States)

The National Guard is a military reserve organization of the United States Department of Defense (DoD). It is composed of reserve components of the United States Army and the United States Air Force: the Army National Guard and the Air National Guard, respectively. It is based in each of the 50 U.S. states, the District of Columbia, and three U.S. territories. Guard components are part of the U.S. Army and the U.S. Air Force when activated for federal missions.

The legal basis of the National Guard is Congress's Article I, Section 8 enumerated power to "raise and support Armies". All members of the National Guard are also members of the organized militia of the United States as defined by 10 U.S.C. § 246. National Guard units are under the dual control of U.S. state or territorial governments and the U.S. federal government.

Most National Guard soldiers and airmen serve part-time while holding a full-time civilian job. These part-time guardsmen are augmented by a full-time cadre of Active Guard and 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. Service was previously represented by the recruitment slogan "One weekend a month, two weeks a year", which was dropped after 2004 as many National Guard soldiers were deployed to active service at the Iraq War.

Colonial militias were formed during the British colonization of the Americas from the 17th century onward. The first colony-wide militia was formed by Massachusetts in 1636 by merging small, older local units, and several National Guard units can be traced back to this militia. The various colonial militias became state militias when the United States became independent. The title "National Guard" was used in 1824 by some New York State militia units, named after the French National Guard in honor of the Marquis de Lafayette. "National Guard" became a standard nationwide militia title in 1903, and has specifically indicated reserve forces under mixed state and federal control since 1933. In the 21st century, state-level Defend the Guard legislation has been proposed that would require a formal congressional declaration of war before National Guard units can be deployed in overseas combat.