“for most of U.S. history, there was little actual legal framework to support any such interpretation of the Second Amendment. It wasn't until a relatively recent Supreme Court decision that this all changed.”

The article you linked to bases its premise on that statement, which is demonstrably incorrect. Any review of the debates on the BoR of the day, in particular of the Federalist Papers and the Anti-Federalist Papers will have little difficulty in discerning the intent of the founders. Concerning court interpretations, as I am not as erudite as most, I'll refer you to this. It is taken from a constitutional commentary from the University of Minnesota Law School (https://scholarship.law.umn.edu/cgi/viewcontent.cgi?article=1275&context=concomm):

"From the enactment of the Bill of Rights through most of the twentieth century, the second amendment seems to have been understood to guarantee to every law-abiding responsible adult the right to possess most ordinary firearms. Until the mid-twentieth century courts and commentaries (the two earliest having been before Congress when it voted on the second amendment) deemed that the amendment "confirmed [the people] in their right to keep and bear their private arms," or "their own arms."

In a 1939 case which is its only full treatment, the Supreme Court accepted that private persons may invoke the second amendment, but held that it confines their freedom of choice to militia-type weapons, i.e., high quality handguns and rifles, but not "gangster weapons" such as sawed-off shotguns, switchblade knives and (arguably) "Saturday Night Specials. " In the 1960s this individual right view was challenged by scholars who argued that the second amendment guarantee extends only to the states' right to arm formal military units. This states' right view attained predominance, and was endorsed by the ABA, the ACLU and such texts as Lawrence Tribe's American Constitutional Law. During the 1980s, however, a large literature on the amendment appeared, much of it rejecting the states' right view as inconsistent with the text and with new research findings on the legislative history, the attitudes of the authors, the meaning of the right to bear arms in antecedent American and English legal thought, and the role that an armed citizenry played in classical liberal political philosophy from Aristotle through Machiavelli and Harrington to Sidney, Locke, Rousseau and their various disciples. Indicative of the current Supreme Court's probable view is a 1990 decision which, though focusing on the fourth amendment, cites the first and second as well in concluding that the phrase "right of the people" is a term of art used throughout the Bill of Rights to designate rights pertaining to individual citizens (rather than to the states)."

There is an easily traced history regarding the Second, clearly showing the intent to protect a naturally-existing right of the individual against incursion by government.

Thanks! I'll look it over after I get home.