To understand the Second Amendment, we need to go back to something like the beginning.
FEUDALISM AND POLITICAL SOVEREIGNTY
In English common law in medieval times, meaning as late as the 13th century, the feudal legal system limited ownership of military weapons to members of the knightly class, and those classes over the knights. In other words, the ownership of weapons had to do with legal status.
The common man, meaning a peasant, could not be called into military service. Military service was a matter of inheritance of land and status, and this inheritance mandated military training, which created a military mindset. Thus, the weapons associated with this class, which was also a matter of social status, were not to be shared with the peasantry. This placed the peasantry at an obvious disadvantage in terms of military power. It also extended to political power. They had little political power. They were represented mainly by priests.
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MILITIAS: REAL AND PHONY
I want to make it clear that I do not believe that it is possible, under anything like present conditions, for Americans to take up arms against the central government. In a period of financial crisis, in which the central government can no longer deliver the goods economically, and which therefore begins to lose its power to control local communities, there may be confrontations between armed camps. The obvious armed camps that I am thinking of are the gangs. The gangs are well armed, and in comparison with most small-town police departments, far better armed than the law enforcement agencies. The police know this. The gangs are ruthless, and they have something like a military chain of command. In a time of national economic breakdown, there will be some communities in which the gangs possess primary authority. This is true today in much of Latin America.
h/t Arctic Patriot