From Bearing Arms:

Tench Coxe, a friend of Madison and himself a delegate to the Constitutional Convention, in discussing the Second Amendment, wrote “civil rulers . . . may attempt to tyrannize,” and rulers might use the power of the military to injure fellow citizens, thus, “the people are confirmed by the article in their right to keep and bear their private arms.” He had earlier also written that “Congress ha[s] no power to disarm the militia. Their swords, and every other terrible implement of the soldier, are the birthright of an American.”