Old enough to go to war, certainly old enough to buy a firearm.
exactly
Exactly! I can't see blocking someone old enough to be sent to war from buying a firearm, or a beer, or whiskey.
1792; U.S. Congress passed the Militia Act.
Two Militia Acts, enacted by the 2nd United States Congress in 1792, provided for the organization of militia and empowered the president of the United States to take command of the state militia in times of imminent invasion or insurrection.
The president's authority had a life of two years and was invoked to suppress the Whiskey Rebellion in 1794. In 1795, Congress enacted the Militia Act of 1795, which mirrored the provisions of the expired 1792 Acts, except that the president's authority to call out the militias was made permanent. The Militia Act of 1862, enacted during the American Civil War, amended the conscription provision of the 1792 and 1795 acts, which originally applied to every "free able-bodied white male citizen" between the ages of 18 and 45, to allow African-Americans to serve in the militias. The new conscription provision applied to all males, regardless of race, between the ages of 18 and 54. The Militia Act of 1903 repealed and superseded the Militia Act of 1795 and established the United States National Guard as the body of the "organized militia" in the United States. {Emphasis added}