It's something I wondered about since hearing a Red Foley song lyric back in the 50's that "history was made by Steamboat Bill"
on the Mississippi by Memphis.
The "history" was apparently an old song recorded by Arthur Collins
in 1910 or 1911.
Buster Keaton made a silent film "Stemboat Bill, Jr."
loosely based on the song in 1928.
And, Walt Disney's first Mickey Mouse cartoon called "Steamboat Willie"
(1928) was a spoof of that film with Mickey whistling the "Steamboat Bill" melody.
So it seems that Steamboat Bill is a fictional character from an old song that was well known in the late 20's, 50's and maybe even now.