The original purpose is actually pretty easy to grok. Let's take this in context. Having just overthrown the British royal government, who's army confiscated firearms whenever they could, then suffered through the Articles of Confederation, the framers wanted very much to support the rights of the people to defend themselves against anything. Not just foreign armies, but any threat to their "life, liberty, and pursuit of happiness". Read the Federalist Papers, those writings are clear.
For those of you who think somehow the 2nd Amendment is about an organized militia, remember the other nine amendments are all individual rights. How odd that a collective right or a state right would be part of the Bill of Rights? Because the 2nd is an individual right. Do I really need to explain the plain language of the 2nd? Remember, the 2nd was written in 1789, and English today is not the same.
Your post seems typical to me of those who take your own agenda and put it in the mouths of the founding fathers.
Yes, the founding fathers had a general sense at the time that having a gun should be the right of people - given that people were expected to contribute to loval security, to be available for the state militia, for hunting for many - there was a broad basis for the right, but if that was their only purpose - that broad individual right - they would have written it like the other amendments, and simply put the last part of the amendment: "The right of the people to keep and bear arms shall not be infringed".
But, they DID make it unique - the only right to have its purpose explained, with a preamble phrase.
You say 'for those who think the 2nd amendment is somehow about an organized militia'.
Well, 'those' include its authors, who qualified the right in its language: 'A well-regulated militia being necessary for the security of a free state, the right...'
So, yiou treat 'those who think the 2nd amendment as somehow about an organized militia' like some kind of bizarre people with an agenda, when it's you ignoring its words.
Language has changed in some ways from 1791, but the basic meaning of what they said about the well-regulated militia being the basis for the right has not.
It couldn't be much plainer, seeing how you simply ignore what it says.
I've never heard a good answer from the people who want the amendment to be a much larger right not based on state militias, why they didn't just include the last part.
THAT is what it would say if they'd meant that these people want to claim.
It doesn't have that sort of qualifier on any other right. It doesn't say, 'public discource without coercion being necessary for the political reasoning in a free state, the right of the people to free speech shall not be infringed.' It doesn't say, 'freedom from the thread of drastic punishment by the state being necessary to the moral behavior of a free state, the right of the people to be free of cruel and unusual punishment shall not be infringed'.
None of the others have some purpose, some limiting function, for the rights specified. But they specifically rejected the naked and unambiguous right you want them to have passed.
The question isn't what the amendment says, the question is whether you will be accurate, or re-write it to fit your agenda, ignoring what it says.
The situation as far as our need for those state militias as our main national defense without a standing army has changed drastically - not the English language about it.
There is some gray area, that while they stated a purpose of collective defense at the state, to meet that purpose they gave what reads as an individual right - albeit one which the Supreme Court has had no problem taking away from some people if there's much of a reason at all, such as someone who commits a crime - and has served the sentence. Why can their right be taken away forever? It doesn't mention that in the amendment.
(Which raises another interesting question - which constitutional rights can be taken from criminals not in custody, forever? Free speech? Freedom from cruel and unusual punishment? The right to keep troops in their home? We seem to have no problem letting states deny them the right to vote; and we let the government deny them the right to freedom from 'unreasonable search and seizure' under the rules of probation that can last ten years or more, in principle forever, in lieu of more prison).
So the amendment has really lost its relevance in terms of its stated purpose of the need for state militias to protect society without a standing army to do it;but we can't just toss aside rights in the constitution. So the best solution would seem to update the amendment. I don't think people can really make a very rational case why the current situation where everyone seems ok with rifles but not automatic guns being protected is based in the amendment - but that distinction is said to come from it.
Many Americans would not doubt like to amend it to strip off the well-regulated militia language - which would still leave the definition of which arms are protected.
Others would like to give states and the federal government clearer rights to have gun control; for example, Milton Eisenhower, the President's brother, just after the second to last time we did pass some federal gun control in 1968, led a presidential commission under Nixon on the issue which called for the confiscation of nearly all handguns.
But since none of these views has the political support for a constitutional amendment, we keep the original, and just write whatever laws our politician judges let be written by 'interpreting' the amendment to mean things it doesn't say - after over 200 years when the Justices finally ruled more on what it said, it was a 5-4 decision, hardly supporting that the definitions they claim were there are clearly there.