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The US National Guard is a reserve military force and is the oldest component of the US armed forces.
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Its birthday is celebrated each December 13.
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It was formed in 1636 as a the militia of the colonists in North America, and is guaranteed by the US Constitution
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The term "national guard" actually came from Revolutionary War hero the Marquis de Lafayette, who popularized the term on an 1824 visit to the US.
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It consists of the Army National Guard and the Air National Guard.
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Each US state, territory and Washington, DC, has its own National Guard
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The National Guard takes an oath to perform state or federal missions and can be deployed for either. A governor can call up troops during civil disturbances or national disasters.
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The president can order troops for federal missions both domestically and in foreign nations.
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In times of peace, the National Guard trains or "drills" one weekend a month and two weeks during the year.
National Guardsmen have fought in every US war since 1637.
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Since Sept. 11, 2001, they've had at least 850,000 deployments overseas.
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