I kind of find this one funny. On this date in 1839, the term “OK” entered our vernacular in the printed form. The Boston Morning Post was talking about the Anti Bell-Ringing Society that took a trip, and they used the term “OK” as a substitute for “oll correct,” a popular misspelling of “all correct.” Allen Walker Reed was the one who uncovered this mystery. He was an American linguist and English professor at Columbia University. He dispelled theories that people had of the origin of this term–everything from an army biscuit (Orrin Kendall) to the name of a Choctaw chief named Old Keokuk. I can’t stand the abbreviation, and I am one of the strange ones who writes out “okay” instead of the abbreviation.
For more information:
http://www.history.com/this-day-in-history/ok-enters-national-vernacular
http://famousdaily.com/history/first-published-use-of-term-ok.html