Militia Act of 1792
RKV suggested a reference to the original militia statute adopted by the First Congress might be interesting, with regard to showing what "militia" meant to the framing generation. Here's the Militia Act of 1792, and the Calling Forth Act. The former's relevant portion is:
"An ACT more effectually to provide for the National Defence, by establishing an Uniform Militia throughout the United States.
I. Be it enacted by the Senate and House of Representatives of the United States of America, in Congress assembled, That each and every free able-bodied white male citizen of the respective States, resident therein, who is or shall be of age of eighteen years, and under the age of forty-five years (except as is herein after excepted) shall severally and respectively be enrolled in the militia, by the Captain or Commanding Officer of the company, within whose bounds such citizen shall reside....
That every citizen, so enrolled and notified, shall, within six months thereafter, provide himself with a good musket or firelock, a sufficient bayonet and belt, two spare flints, and a knapsack, a pouch, with a box therein, to contain not less than twenty four cartridges, suited to the bore of his musket or firelock, each cartridge to contain a proper quantity of power and ball; or with a good rifle, knapsack, shot-pouch, and power-horn, twenty balls suited to the bore of his rifle, and a quarter of a power of power; and shall appear so armed, accoutred and provided, when called out to exercise or into service, except, that when called out on company days to exercise only, he may appear without a knapsack. That the commissioned Officers shall severally be armed with a sword or hanger, and espontoon; and that from and after five years from the passing of this Act, all muskets from arming the militia as is herein required, shall be of bores sufficient for balls of the eighteenth part of a pound; and every citizen so enrolled, and providing himself with the arms, ammunition and accoutrements, required as aforesaid, shall hold the same exempted from all suits, distresses, executions or sales, for debt or for the payment of taxes."
The Act remained on the books until 1903, when the Dick Act replaced it with the language now found in 10 U.S. Code sec. 311:
"Militia: composition and classes
(a) The militia of the United States consists of all able-bodied males at least 17 years of age and, except as provided in section 313 of title 32, under 45 years of age who are, or who have made a declaration of intention to become, citizens of the United States and of female citizens of the United States who are members of the National Guard.
(b) The classes of the militia are--
(1) the organized militia, which consists of the National Guard and the Naval Militia; and
(2) the unorganized militia, which consists of the members of the militia who are not members of the National Guard or the Naval Militia."