During colonial America, all able-bodied men of certain ages were eligible for the militia. Individual towns formed local independent militias for their own defense. The year before the US Constitution was ratified, The Federalist Papers detailed the founders' vision of the militia. The new Constitution empowered Congress to regulate this national military force, leaving significant control in the hands of each state government.
Today, as defined by the Militia Act of 1903, the term "militia" is primarily used to describe two groups within the United States:
The term "militia" derives from Old English milite meaning soldiers (plural), militisc meaning military and also classical Latin milit-, miles meaning soldier.
The Modern English term militia dates to the year 1590, with the original meaning now obsolete: "the body of soldiers in the service of a sovereign or a state". Subsequently, since approximately 1665, militia has taken the meaning "a military force raised from the civilian population of a country or region, especially to supplement a regular army in an emergency, frequently as distinguished from mercenaries or professional soldiers".