This is the interpretation set forth by the United States Congress, not in 1776, but last week. In an amicus curiae brief (pdf) signed by 55 Senators and 250 Representatives, the Congress has taken a stand in favor of individual liberties.
In sum, the Second Amendment guarantees an individual right to keep and bear arms. Recognition of that right promotes the well regulated militia necessary for a free State’s security.
They’re not the only ones, either.