Per the response I got, the flag is a 1778-documented hand-stitched flag made by a flag expert named Steven Hill. They also sent this link to the following description of the flag from the Franklin Papers:
It is with Pleasure on this occasion that We acquaint your Excellency, the Flagg of the United States of America, consists of thirteen Stripes, alternately red, white and blue;—a small Square in the upper angle next the Flag Staff is a blue Field, with thirteen white Stars, denoting a new Constellation.
I had previously come across the Serapis (or John Paul Jones) Flag, which was the closest match in terms of image that I was able to find to L’Hermione‘s flag, but the blue stripes are in an irregular pattern that doesn’t correspond. The Serapis Flag was created out of necessity. John Paul Jones took command of the the conquered British HMS Serapis after his own ship was lost in battle.When Jones later arrived in a Dutch port sailing his captured ship, he needed a flag in a hurry, to avoid being treated as a pirate. And so the Serapis Flag was created. The Serapis Flag is thought to have possibly been based on Franklin’s description, although it is curious that he ended up with such a peculiar stripe pattern, which is certainly not indicated in the text.
Although the familiar red and white stripes had been adopted in the 1777 Flag Resolution, Franklin had been in France since a few months prior. Perhaps the final details just hadn’t gotten to him yet?
At any rate, given the variety of flag designs of the time, it’s almost surprising I wasn’t able to find an exact match to L’Hermione‘s flag. There were certainly a few that were quite similar.
I was really hoping the rationale would have a more direct connection to the original Hermione – perhaps evidence that she actually flew under a flag of that particular design. I am still rather glad they chose a more obscure flag, as I learned quite a bit as I tried to find some answers.
Happy belated Flag Day!