Even though it is not a federal holiday, the birthday of the U.S. National Guard is celebrated on December 13 and is an important event to note. Established in 1636, the National Guard is the oldest military organization in America. Its members serve during times of war and emergency.
The United States National Guard is part of the reserve components of the United States Army and the United States Air Force. It is a military reserve force composed of National Guard military members or units of each state and the territories of Guam, the Virgin Islands, and Puerto Rico, and the District of Columbia, for a total of 54 separate organizations. All members of the National Guard of the United States are also members of the Organized Militia of the United States. National Guard units are under the dual control of the state governments and the federal government.