Where did the word okay(o.k.) come from?

Answer 1

: 1. Orrin Kendall biscuits, which soldiers ate during the Civil War.
: : 2. Short for Aux Cayes, a Haitian port that American sailors praised for its rum.
: : 3. Old Keokuk, a Native American tribal chief who was said to have signed treaties with his initials.
: : 4. OK stands for "all correct" or the illiterate phrase "Orl Korrect."
: : 5. U.S. President Martin Van Buren's nickname "Old Kinderhook" -- OK for short. He was a native of Kinderhook, N.Y.
: : 6. Choctaw word "okeh," (or "hoke") meaning "indeed" (or "It is so.")
: : 7. Scottish "auch aye", meaning "ah yes." (Or "och aye," meaning "okay.")
: : 8. From the French maritime phrase "au quai" meaning "at dock", and therefore at last safe from the ravages of the open sea.
: : 9. '0 killed' - the report of the night's death toll during the First World War.
: : 10. All clear after the shoot-out at O.K. Corral.
: : 11. Instruments calibrated at an Observatory at Kew had, affixed to them, a stamp, or impression, to authenticate that calibration. This stamp was O K - Observatory Kew.
: : 12. The abbreviation is for Oberst Kommandant, German for "Colonel in Command," used by either -- take your pick -- a General Schliessen or Baron von Steuben when initialing letters and orders during the American Revolution.
: : 13. It comes from the name of a freight agent, Obadiah Kelly, whose initials were widely disseminated on bills of lading.
: : 14. The abbreviation is for Open Key, popularized by telegraphers in the 1860s.
: : 15. It comes from the names of Lords Onslow and Kilbracken, who initialed bills after they were read and approved in England's House of Lords.
: : 16. From a misreading of "Order Recorded" on official documents.
: : 17. Or from Finnish "oikea," correct.
: : 18. From the Greek "olla," all, plus "Kalla," good.

Answer 2

O.K. actually dates back to the 1830's. Boston newspapers started printing this word as a variant spelling of "all correct" (oll korrect). There was a Democratic presidential candidate Van Buren, whose nickname was Kinderhook. So, through wordplay O.K. was changed to mean "Old Kinderhook", which became part of his political platform since "everything would be OK" if he were elected president. This helped the word gain much popularity.

Answer 3

Ive heard 2 theories: in a letter in the Vancouver Sun, in 1935, it was pointed out that early schoolmasters would mark examination papers by adding the Latin "Omnis Korrecta", which was sometimes abbreviated to OK. Other suggestions include: '0 killed', as used by soldiers in World War I to report deaths each evening, that's why we associate "ok" with "fine".