No you didn't. 'Intent' is a noun that's the object of the preposition 'by' modified by the adjective 'original'. Nothing adverbial there at all. Try again.
Konrad is 100% correct here.
If "original intent" were an adverbial phrase -- what would it modify?
Very interesting thread, and the distinction between the collective "people" and individual "person" is a fascinating lead. Konrad, you may be the only poster I've seen today who's not only familiar with English but proficient at it.
I don't see an issue with the comma there or not there if we're looking at the last one. I don't even see its function. Whether militia is capitalized or not has an interesting theory in the link. I would point out that at the time of the writing we were still capitalizing nouns as a holdover from our parent language German, although this was dying out at this time and that may account for the change from majuscule to minuscule. Or it may not. Another fascinating lead.
I would just add that if the intent and interpretation of Amendments were clear prima facie, then we wouldn't need a Supreme Court to address them.
And the Court has addressed this Amendment. Consistently ruling that military type weapons in "common use" are what is protected and that it conveys an INDIVIDUAL right.
That prolly depends on how it was / could be argued.