What is the National Guard?

The National Guard is the official militia force of the United States. The National Guard is established and owned by all U.S. states, territories, and the District of Columbia. The National Guard is a part time force, with the majority of service members drilling only one weekend a month and two weeks out of the year while they simultaneously hold civilian jobs. The National Guard is both a federal and a state fighting force, the the federal government holding the ability to activate service members to federal status when needed.
Due to their state function, National Guard troops are able to deploy within their own state or territory. Many states use this function to deploy Guardsmen for disaster relief, border security, or to declare martial law in a dire situation.
Some in the National Guard trace their existence back to 1636, with the Spanish establishment of a colonial militia force in the modern state of Florida. However, the National Guard as it is today was officially established in 1903 by order of Congress for a federally recognized militia.