There are dozens of other interpretations, all equally knuckleheaded. OK = oll korrect, that’s good enough for me.
(1) It’s a derivative of the Choctaw Indian affirmative “okeh.” Andrew Jackson, who figures in many stories about OK, is said to have introduced the word to the white man.
(2) Another Jackson story has it that he used to mark OK for “oll korrect” on court documents. In the one example of this that was actually unearthed, however, the OK was found actually to be OR, for “order recorded,” a common courthouse abbreviation.
(3) It was a telegraphic signal meaning “open key,” that is, ready to receive. Others say OK was used for “all right” because A and R had already been appropriated for other purposes. Big problem with this theory: the first telegraph message was transmitted in 1844, five years after OK appeared.
(4) It stands for O. Kendall & Sons, a supplier of army biscuits that stamped its initials on its product.
(5) It comes from Aux Cayes, already discussed. A variant is that it comes from the French au quai, “to the dock,” said of cotton that had been approved for loading on a ship.
(6) It stands for Obediah Kelly, a railroad freight agent, who used to mark his initials on documents to indicate all was in order.
(7) It comes from the Greek Olla Kalla, “all good.”
(8) A German general who fought on the side of the Americans in the Revolutionary War used to sign documents OK for Ober-Kommando.