You are already a member of a militia in the US - it's called the state militia, (which in NOT the National Guard). And while it falls outside of formal military service, (Regular military, Reserve, or Guard), it does exist and you are a part of it from ages 17 to 55 or so. And in some states even women are subject to it equally. There are contingencies upon contingencies that already exist for this and have for a very long time.
This is a decent, and not super complicated overview of most of the military organizations and how they interact.(https://www.youtube.com/watch?v=nAsZz_f-DUA) The state militias part come towards the end.
I am a bit familiar with this as a medic who asked a dumb question, I was told we were subject to, (though it takes a really major disaster), to being "called up" by the Dept of Homeland Security to go and supply aid if needed and where needed. If I remember correctly some few were either called up or were close to being called and assigned during the last major hurricane in New Orleans. I'm old and retired now and I am no longer subject due to age.
So perhaps you should get that musket and start training...........
it does exist and you are a part of it from ages 17 to 55 or so.
Wait a minute. Are you saying that there is an age and gender restriction on a civil right? Males have a constitutional protection that women do not have and the young have one the elderly do not? That's very interesting. Does it apply to any other rights?
The age and gender requirements come from the legislature, not the Constitution. Constitutionally, the militia is everyone. If militia membership is required for gun ownership under the 2nd Amendment, we have to use the Constitutional meaning of "militia" which is everyone.
Legislatively, the militia is defined in 10 USC § 246, the unorganized class of which is comprised of all able-bodied male citizens and those who intend to become citizens, aged 17 to 45.
Congress can change the legislative definition. They cannot alter the constitutional meaning.
The right of the people to keep and bear arms shall not be infringed. A well-regulated militia, composed of the body of the people, trained to arms, is the best and most natural defense of a free country.”
-James Madison, June 8, 1789, I Annals of Congress 434
“I ask who are the militia? They consist now of the whole people, except a few public officers.”
- George Mason, June 4, 1788, Address to the Virginia Ratifying Convention
"A well regulated militia, composed of the Yeomanry of the country, have ever been considered as the bulwark of a free people.”
Alexander Hamilton
Read also the Federalist papers, especially 29 and 46.