So says James Garland here:
According to the state code, “the unorganized militia shall consist of all able-bodied male residents of the state between the ages of 17 and 45 who are not serving in any force of the organized militia or who are not on the state reserve list or the state retired list and who are, or who have declared their intention to become, citizens of the United States.” Thus, the vast majority of military-aged men in the state are in the unorganized militia, whether they realize it or not. ...
[T]he long-established expectation concerning volunteer organizations such as the State Defense Force and the unorganized militia is that they outfit and equip themselves. They traditionally have been expected to arm themselves and be ready to take action on behalf of the community should the need for such action arise. Given this fact, any contention that the Second Amendment prohibits the private possession of firearms would seem irreconcilably flawed.