> Or maybe they would have been scared completely senseless seeing tons of steel being piloted by an idiot with no training at speeds they didn't even know were possible for humans to achieve.

In light of the second amendment, that seems unlikely.

Automobiles are far more deadly than any 18th century firearm.

The Founding Fathers approved of personal ownership of battleships, hence the "letters of marque" clause in the constitution.

Isn't a letter of marque basically a primitive license?

I think it's funny that both of these replies center on refuting my idea that they might be frightened, but ignore the more important idea that what they would or would not think is not important.

License to initiate warfare under authority of Congress, yes. License to own and operate harmlessly one defensively, no.

The philosophy of the Founding Fathers is extensively documented. Not the least of which is their carrying out revolt and secession against a superpower for the purpose of securing personal liberty and minimizing control & harassment by government. In light of that, the notion of them fearing cars and using government to restrict ownership thereof by punishing lack of paperwork is absurd.

I don't think it's absurd to imagine that something so completely beyond what they could have even imagined might have hit them on a deep, irrational, emotional level.