And before that time, during the time that the nation was being formed, the entire military (including the navy) was made up of the people and the privately owned weapons they brought with them.It's hard to be dogmatic, but given that the arms of the people WERE the arms of the nation, there's a good case to be made that any weapons of the time were protected.
This is not true. There was a Continental Navy of 64 ships controlled by the Revolutionary Government. They were by the way more successful, on a percentage basis, in capturing British ships. The arms of the Regulars of the Continental Army were not the arms owned by individual the people. Sure some personally owned arms were used, especially by militia troops, but the Regulars were primarily armed by the government.
Even if we accept, for the sake of argument, that the protection extended to armed ships which are not overtly military warships but not to the most powerful warships of the day, it still makes it clear that the line of what is protected and what is not is drawn far, FAR above the power level of any conceivable small arm.It's a huge world and it's possible to find support for nearly any opinion. In reality there was no analog for WMDs until WMDs were developed. That's why the entirely new classification was created.
However, if we accept for the sake of argument, your claim that the best warships of the time are analogous to WMDs and, again for the sake of the argument accept your claim that the best warships of the day were prohibited then my statement would still be accurate.
The term “weapons of mass destruction” pre-dates (at least as early as 1937) nuclear and modern biological and chemical weapons. There are many definitions defining WMDs from various organizations. A very simple definition from Wikipedia is “Any weapon that can kill and bring significant harm to a large number of humans or cause great damage to human-made structures (e.g. buildings), natural structures (e.g. mountains), or the biosphere. I don’t think it much of a stretch to consider any weapon that can destroy a city to be a weapon of mass destruction. In the 18th Century a 1st Rate Ship of the Line having as many as 150 guns, with guns as large as 48 pounders, could by itself destroy many of the coastal cities in the 18th Century World. The demolition, burning, and killing would just be done much more slowly than can be done with todays WMDs.
"...the only reasonable conclusion would be that the 2nd was intended to protect the private ownership of any weapons up to but probably not including weapons of mass destruction."
The bottom line is that a realistic evaluation of the history and weapons of the time makes it abundantly clear that the 2nd, as originally intended, would absolutely not prohibit any small arm of any kind and would likely only place the most potent weapons of our time outside of the legal realm of possession without explicit governmental permission.
Certainly a strong case can be made for that interpretation of 2nd Amendment rights.