Word Origin & History
1845, Amer.Eng., probably from the familiar version of the proper name Joshua, but just which Joshua, or why, is long forgotten. Perhaps it was taken as a typical name of an old farmer. The word was in use earlier than the career of U.S. humorist "John Billings," pseudonym of Henry Wheeler Shaw (1818-85),
who did not begin to write and lecture until 1860; but his popularity after 1869 may have influence that of the word.
About the most originality that any writer can hope to achieve honestly is to steal with good judgment. ["Josh Billings"]