I've enjoyed Eggs Benedict for as long as I can remember, but I've never known where the name (or the recipe) originated. Thanks to Atlas Obscura, all is now revealed.
The most important thing to know about eggs Benedict is that they have nothing to do with the famed traitor Benedict Arnold.
In fact, some give credit for the dish to Pope Benedict XIII, who ruled the Vatican from 1724 to 1730, and was put on a strict eggs and toast diet while there–dressed in a lemon-based sauce, at his request. But it wasn’t eggs Benedict, exactly, and that pope’s ultimate legacy was sartorial, not culinary: he forbade the wearing of wigs by the cardinals.
Pushing aside stories of traitors and popes, it seems the real source of eggs Benedict was New York City in the Gilded Age, an era when rich people were starting to party in public instead of private homes, in plain view of commoners who also liked staying out late and spending money in restaurants.
There's more at the link.
There look to have been two possible claimants to fame, although I understand neither can be confirmed with 100% accuracy. Still, the location and approximate era of the invention of Eggs Benedict seems to have been nailed down with reasonable certainty.
(By the way, there are many interesting variations on Eggs Benedict. Wikipedia helpfully provides a list. I think I'm going to take it as a personal challenge to sample every one of them!)