[StJacques]

". . . The militia was expected to show up with current military hardware. How were merchantmen expected to arm their vessels with cannons after being granted Letters of Marque and Reprisal?"

"Letters of Marque and Reprisal" are papers of authorization given by the government, which implies regulation, since the legitimacy of action derives from government sanction.

[Dead Corpse]

Not quite. Letter's of M&R were authorization for privateers, already armed, to act on behalf of the government in a legal capacity. No more. No less. They were also loot sharing agreements as well. Government got its armed ships, Captains gave govt a cut of anything they captured.

[neverdem]

"Letters of Marque and Reprisal" are papers of authorization given by the government, which implies regulation, since the legitimacy of action derives from government sanction.

Merchant owners already armed their vessels to defend against pirates.

[Wonder Warthog]

""Letters of Marque and Reprisal" are papers of authorization given by the government, which implies regulation, since the legitimacy of action derives from government sanction."

But the "action" in question is ATTACKING CERTAIN NATION'S SHIPS. NOT arming those vessels. They were ALREADY so armed, even when in private usage.