Here's an interesting thought; what do we actually know about this guy?
Judging from Mr. Jefferson's letter in reply, we may infer that William Short, like Jefferson, positively identified himself as an Epicurean. Cassius' recent reading of Frances Wright's other work has me thinking that there might be gems hidden here as well.
He was a talented, capable, brilliant protégé of Thomas Jefferson, and a deft hand at diplomacy. He forsook the dream of a high and polished political career in his pursuit of the love of a French Noblewoman. Despite his career disappointments, he was an accomplished businessman, and retired wealthy while Jefferson himself slipped into debt and penury at the end of his life. He was George Washington's first appointment to office. He loved the new American project, but preferred living in Europe.
Some of his correspondence with the married French Duchess survive. I haven't yet found the texts online, but they might be worth perusing.
Here's an interesting anecdote; one day while canoeing on the Seine with Rosalie (whose much older husband in a marriage of convenience evidently didn't object to their affair), William noticed a boy on the verge of drowning. He dove into the waves to save the boy, and nearly lost consciousness in the rescue. When the party returned to the Nobleman's Chateau, he was treated to a banquet and lauded as a hero. It's probably a coincidence, but the story bears remarkable similarities to Theon's rescue of Hedeia in A Few Days in Athens. (This happened in 1790; Wright published in 1822).