Obviously the nature of warfare has changed a bit since 1790. Should civilians be allowed to have the same weaponry legally that is possessed by our military in every sense as long as they can afford it? Where would we draw the line and why? I know we use as civilians some of the same weapons but how do we advocate gun ownership and refute the "you are extremists who want to carry grenade launchers around"
It has changed, but even in 1790, a cannon was a pretty destructive thing, with few peaceful, civilian applications. Do you think it was reasonable for the (British) government to try to take the cannons at Lexington and Concord from the local militias?
Back then, a warship was the most powerful weapons system of the day, and President James Madison didn't seem to have a problem with civilians possessing them. He even hired them.