The word OK has found its way into just about every language on earth. Although it’s usually written in all capitals and pronounced as separate letters, OK is a word and not an acronym, although it began as one.
The most likely origin of OK is as an acronym for “Oll Korrect,” a deliberate misspelling of “all correct.”
In the years before the American Civil War (1861-1864), journalists thought it was great fun to misspell words for comic effect. Writer Charles Farrar Browne (1834-1867), for example, wrote political humor under the byline Artemus Ward. Abraham Lincoln is said to have been one of his greatest fans. Here’s a passage in which he takes a stand against secession:
Feller Sitterzens: I am in the Sheer & Yeller leaf. I shall peg out 1 of these dase. But while I do stop here I shall stay in the Union…I shall stand by the Stars & Stripes. Under no circumstances whatsomever will I sesesh. Let every Stait in the Union sesesh & let Palmetter flags flote thicker nor shirts on Square Baxter’s close line, still will I stick to the good old flag.
Fellow Citizens: I am in the sere and yellow leaf [I’m old]. I shall peg out [die] one of these days. But while I do remain here I shall stay in the Union…I shall stand by the American flag. Under no circumstances whatsoever will I secede. Let every State in the Union secede and let Palmetto flags float thicker than shirts on Squire Baxter’s clothes line, still will I stick to the good old flag.
Note: “The sere and yellow leaf” is an allusion to a line from Macbeth. The Palmetto flag was the state flag of South Carolina; it was flying over Fort Sumter on the day the Union garrison surrendered to Confederate forces. Squire Baxter is a fictional character of Ward’s invention.
Ward was not the only writer to adopt deliberate misspelling as a stylistic device. By 1839, the misspelling “oll korrect” for “all correct” had been compressed to O.K. and was familiar to newspaper readers on the East Coast at least:
Boston Evening Transcript 11 Oct. 2/3, 1839. Our Bank Directors have not thought it worth their while to call a meeting, even for consultation, on the subject. It is O.K. (all correct) in this quarter. –OED citation.
When O.K. became associated with the presidential campaign of Martin Van Buren (1782-1862), its use spread throughout the nation.
One of Van Buren’s campaign ploys was to associate himself as much as possible with the previous president, Andrew Jackson. Jackson had been known affectionately as “Old Hickory,” so Van Buren came up with the nickname “Old Kinderhook,” an allusion to the small New York town that was his birthplace. The abbreviation O.K. for “Old Kinderhook” became a rallying cry and a logo. The press lost no time in connecting the O.K. of Van Buren’s political slogan with the O.K. that stood for “all correct.” By the end of the campaign, “O.K.” was entrenched in American English throughout the country.
In addition to its adjectival uses to denote things that are “all correct,” OK is also used as noun, verb, adverb, and interjection.
Note on the word “acronym”
In general usage, acronym refers to words or letter groupings like FBI, TGIF, NATO, and LASER. Some speakers prefer to reserve the word acronym for words like NATO that can be pronounced as words and use the term initialism for letter groupings that are pronounced as a series of letters, like FBI.