They might of thought differently if they had weapons such as: machine guns or semi automatic rifles with bump stocks that could shoot almost 600 people in less than 12 minutes! Guns were meant for survival, whether it was for food or protection, you didn't have to worry about someone with a machine gun or semi automatic weapon going into a movie theater, school house, night club or concert looking to kill as many innocent civilians as they could. Time's were different then and they are much different today.
The Founding Fathers would have thought an AR15 is rad AF. Do you honestly think that guys who were willing to kill or be killed in a duel would have been concerned about civilians owning semi-auto assault rifles in 2017? That's how Alexander Hamilton met his fate. Can you imagine Alan Greenspan going out like that?