the American Bonaparte's aren't exactly....proper Bonaparte Royalty as Napoleon I excluded them from any succession rights, IIRC. Nappy III did allow them to use the Bonaparte name, but not included them in any form of Royalty or the family itself, as I understand it.
Technically, Jérôme had married without his brother's consent, and was forced to divorce his American wife.
Then Napoléon III did aknowledge them mostly to piss off his cousin, Prince Napoléon, whom he distrusted, for which reason he had in one of the early succession laws he enacted early (before his son's birth in 1856), provided for the possibility to adopt an heir from any other branch of the family...
That said, the true black sheeps of the family were the Lucien branch (
see Prince Pierre-Napoléon and his murder of journalist Victoir Noir in 1870).
IOTL, Charles Joseph didn't have children and the American branch died off with him, but I wonder if that might change ITTL. Besides, he was still a few years younger than Elihu Root. If he had a son, the timing of his OTL marriage would have him in his mid thirties, perhaps a veteran of the war, and with daddy's influence, he might get some junior position in the oncoming administration, and rise to prominence under the perhaps Pershing administration in the 1930s (
oops, too soon ?).
At the very least, I'm curious to see what they could do at state level in Maryland, with Charles's progressive credentials, the circumstances of the Confederate invasion, and his relationship to President Hughes (
the Bonaparte-Pattersons would probably count among that Democratic state's most prominent Liberal figures, especially with his advocacy of civil rights for African-Americans, so I'd likely see daddy and junior crossing paths with Hughes during the invasion and at Philadelphia).