Etymology Of Okay (Or, Okay, "OK")
“On 23 March 1839, OK was introduced to the world on the second page of the Boston Morning Post, in the midst of a long paragraph, as ‘o.k. (all correct)’. OK may have originated from a comical misspelling How this weak joke survived at all, instead of vanishing like its counterparts, is a matter of lucky coincidence involving the American presidential election of 1840.”
— I prefer to spell it “okay,” because it’s a word I don’t think should stand out so much. But Allan Metcalf’s etymology of “America’s Greatest Word” is so interesting, however he chooses to spell it is just fine with me.