I have a question. IIRC, every white man between 18 and 45 is required by the 1792 Militia act to enroll in the Militia and arm themselves with a Musket, powder, and cartridges.
So on paper the US should have over 1 million armed militia troops. The question is however how widely was this obeyed?
the militia system never worked well. They were supposed to own weapons and supposed to drill once a month too. However, 'drill' ended up being a social event where everyone brought their families and had a big picnic and bbq; there was about 10 minutes of marching in ranks to make up drill, nobody even bothered to practice shooting. A fair sized chunk of the militia didn't even own weapons. In times of war, the regular army hated the militia units; in the Mexican War, these units behaved abominably and were damn near uncontrollable. The generals at the time wanted dearly to send them home.