Did Benjamin Franklin almost cause a war between England and France over a hoax letter to a London newspaper?

Question

This story shows up a lot in sites like Reddit:

In the late 1700's, a letter appeared in the major London newspaper complaining that England was being forced to take deported French prisoners. The British were furious and wanted it stopped. The French became upset - because the uproar implied that England was too good for French prisoners. Both governments became involved, and they were on the brink of war before it all unraveled as a hoax. The original letter, it was learned years later, had been written by Benjamin Franklin - who was spending 6 months in England as an ambassador - and was simply bored. Just stirring up trouble and sitting back and watching.

I got curious if it really happened and dug around. I didn't find any sources, but I'd like to confirm if it was true or not.

Answer 1

There is a fragment of truth in the story, barely enough to see where it originates.

In 1773 Benjamin Franklin was staying in London.

On 22 September 1773 the The Public Advertiser published a hoax letter An Edict by the King of Prussia, written by Franklin.

The edict does discuss England being forced to take prisoners, but Prussian, not French. The exact language is:

We do hereby also ordain and command, that all the Thieves, Highway and Street-Robbers, House-breakers, Forgerers, Murderers, So[domi]tes, and Villains of every Denomination, who have forfeited their Lives to the Law in Prussia, but whom We, in Our great Clemency, do not think fit here to hang, shall be emptied out of our Gaols into the said Island of Great Britain for the BETTER PEOPLING of that Country

So the true parts of the OP are that Franklin was in London, did have a hoax letter published in a major London newspaper, and the letter did mention Great Britain being forced to take deported prisoners. The statement that he was an ambassador is loosely true, not in the sense of representing one country to another, but in a more general sense. He was originally sent to London to ask the King to change the status of Pennsylvania.

The false part is "French" versus Prussian. The "war" part is also false, but see the block quotation of a letter from Franklin to his son at the bottom of page 55 in The Selected Works of Benjamin Franklin, where he says "What made it more noticed here was that people, till they got half through...imagined it was a real edict".