As a linguistic phrase, OK is something of a phenomenon, traveling from American English into hundreds of other languages. And there are tons of myths about how OK emerged to mean that things are hunky-dory. But which story is correct? The truth is a little bit goofy.
In his book Word Myths: Debunking Linguistic Urban Legends, David Wilton points to a ton of apocryphal stories about the origin of modern language's favorite thumbs-up: Some claim that it comes from the Greek phrase olla kalla, meaning satisfactory. Others say that Andrew Jackson adopted the Choctaw word okeh. Some hold the telegraph responsible, saying it comes from the term Open Key.
But, Wilton notes, Allen Walker Read, a Columbia University etymologist, solved the mystery in the 1960s and shared it with the journal American Speech. Read traced the term OK to 19th-century Boston. During the summer of 1838, editors at Boston newspapers became fond of using abbreviations — not unlike the abbreviations we see on the Internet and in text messages today. For example, an editor might write the phrase "Give the Devil his Due" as "G.T.D.H.D." or "Small Potatoes" as "S.P."
But the abbreviation fad didn't stop there. It mutated, so that the editors would sometimes use, not a proper abbreviation, but a cheekily misspelled one. For example, the phrase "No Go" might be abbreviated not as "N.G." but as "K.G.," just for fun. And so, on one fateful day (namely, March 23, 1839), the Boston Morning Post introduced us to O.K., printing:
...perhaps if he should return to Boston, via Providence, he of the [Providence] Journal, and his train-band, would have the "contribution box," et ceteras, o.k.—all correct—and cause the corks to fly, like sparks upward.
Basically, the editor of the piece abbreviated "all correct" as if it were spelled "oll korrect." The abbreviation fad — and the term "OK" — traveled to newspapers in other cities: New York, Philadelphia, and New Orleans. That's the silly part, but politics may have played a role as well.
One common explanation for "OK" is that it comes from President Martin Van Buren's nickname "Old Kinderhook," and there is probably some truth to this. While Van Buren's nickname isn't the origin of the abbreviation "OK," Read says it helped the term take root. In 1840, a group of Van Buren supporters started the OK Club, likely trading on the popularity of the term "OK." The term shows up all over the Van Buren campaign, in pamphlets, in newspapers, shouted at conventions. And so the implication was that Martin Van Buren wasn't just Old Kinderhook — he was also OK.
And so, "OK" went from a bit of playful spelling to a phrase firmly planted in the English language, one that traveled from the pages of a Boston newspaper into the mouths of people around the world.