In the 18th Century, the Militia was, simply, the people. Basically, males from 16 to 60 were ALL in the militia. So when they composed the 2nd Amendment, since the the militia was basically everyone, they meant the people.
It's kind of fun to go and study the language from back then. Kind of like "well-regulated"... having the meaning it did then, compared to how we interpret it today.
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