In 1791, on this fateful day the House of Representatives accepted the change made to the Second Amendment by the Senate to wit "the right to bear arms [in the service of the State militia]". The original wording had of course been more ambiguous about gun ownership for the purpose of self-defence by private citizens or indeed the ad-hoc formation of citizenry into local militia "A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed".
The Repeal of the Second AmendmentThe libertarian significance of this revision was to place security in the hands of the States who as a final resort could overthrow an oppressive Federal Government. And of course that measure was only tested once in 1861-5, after which the Amendment was repealed.
Otherwise, [it was argued] America might now be a dystopian society with neighbourhood militia delivering vigilante justice. But of course that argument was turned on its head when an ad-hoc civilian militia saved thousands of innocent American lives by storming the cockpit of the Boeing 757-222 on September 11, 2001.