NOTE on WMD and heavy weapons.
Political officials interpreted the Greatest Common Good and General Welfare of the people being to proscribe the private, unlicensed ownersip of heavy weapons in the general population. A light armament is described as non-explosive, non-incendiary single loading or semi-automatic-loading firearms of any caliber up to .50 caliber. Any firearm sold legally in the nation must conform to that criteria. A heavy weapon is any fully-automatic, explosive, incendiary or armor-penetrating device or weapon. The idea after the Civil War was to return the nation to a peaceful, cooperative mode without allowing small, disgruntled factions from easily obtaining the means to victimise/disrupt the civil society.*
It was not necessary for a person to have the right to own an artillery piece or store it in their backyard. The civil authorities were dedicated to peaceful, lawful transmission and administration of order. There was no foreseeable, legitimate purpose for the population to take up the role of soldier because of the permanent military's existence.
So, they passed laws to confine ownership and operations of heavy weaponry to the federal, state and local governments.
Light arms are another matter altogether.
* Legal things like capital equipment, chemicals, industrial materials may be transformed into a heavy weapons - a crime in itself. Once trasnformed, they become illegal but not before. A passenger jet under normal control is a form of transportation. Under control of Mohamad Atta, it is a WMD. At bull dozer is a tool to clear a building site so that construction can begin, unless being driven by someone who wants to level an entire town by himself.