That is why we do not have Howitzers in the driveway.
If you have the cash and desire then you can have a Howitzer. They are not included in the so-called assault weapon ban.
Who are you shilling for?
That's right it doesn't, which means keeping and bearing of all arms is protected. As far as the Courts go, the Supreme court hinted, but that's all they did, in Miller (also see Miller documents) that militarily usefull arms was the test. In fact only a few years later, the appeals court in Cases aknowledged that was what the Supreme Court said. From the "Cases" decision:
Apparently, then, under the Second Amendment, the federal government can limit the keeping and bearing of arms by a single individual as well as by a group of individuals, but it cannot prohibit the possession or use of any weapon which has any reasonable relationship to the preservation or efficiency of a well regulated militia. However, we do not feet that the Supreme Court in this case was attempting to formulate a general rule applicable to all cases. The rule which it laid down was adequate to dispose of the case before it and that we think was as far as the Supreme Court intended to go. At any rate the rule of the Miller case, if intended to be comprehensive and complete would seem to be already outdated, in spite of the fact that it was formulated only three and a half years ago, because of the well known fact that in the so called "Commando Units" some sort of military use seems to have been found for almost any modern lethal weapon. In view of this, if the rule of the Miller case is general and complete, the result would follow that, under present day conditions, the federal government would be empowered only to regulate the possession or use of weapons such as a flintlock musket or a matchlock harquebus. But to hold that the Second Amendment limits the federal government to regulations concerning only weapons which can be classed as antiques or curiosities, -almost any other might bear some reasonable relationship to the preservation or efficiency of a well regulated militia unit of the present day,-is in effect to hold that the limitation of the Second Amendment is absolute. Another objection to the rule of the Miller case as a full and general statement is that according to it Congress would be prevented by the Second Amendment from regulating the possession or use by private persons not present or prospective members of any military unit, of distinctly military arms, such as machine guns, trench mortars, anti-tank or anti-aircraft guns, even though under the circumstances surrounding such possession or use it would be inconceivable that a private person could have any legitimate reason for having such a weapon.
So the "Cases" Court didn't approve of the "Miller" rule, and chose to disregard it as "not general". Which is hardly the normal Appeals court response to Supreme Court decisions, especially recent ones.
Besides, there are some people with howitizers in their driveway, or at least their gargage/shed, and not merely deactivated ones either.