Earliest known appearance in print: 1880 (see Comments below).
Earliest known appearance in print, attributed to Thomas Jefferson: 1983
Other attributions: Andrew Jackson; Mark Twain; G.K. Chesterton; W.C. Fields
Status: We currently have no evidence to confirm that Thomas Jefferson ever said or wrote, "I have nothing but contempt for anyone who can spell a word only one way," or any variation thereof.
Comments: This saying and other similar variations have been attributed to numerous people, as well as appearing in print as an anonymous witticism. The Yale Book of Quotations traces its print origins back to at least 1880; Ralph Keyes, in The Quote Verifier, concludes that it is simply an "old gag."
↑ To establish the earliest appearance of this phrase in print, the following sources were searched for the phrase, "spell a word only one way": Google Books, Google Scholar, Amazon.com, Internet Archive, America's Historical Newspapers, American Broadsides and Ephemera Series I, Early American Imprints Series I and II, Eighteenth Century Collections Online, 19th Century U.S. Newspapers, American Periodicals Series Online, JSTOR.