The term O.K. is attributed to American president Andrew Jackson. During his 1828 election campaign, he was vilified by the opposition for being illiterate, especially for writing all correct as orl korrect.
According to Eric Partridge in The World of Words: An Introduction to Language in General and to English and American in particular (1938):
“It was only in the 1840’s that O.K.! became general in the U.S.A. for ‘all correct!’, ‘right!’, ‘safe!’, ‘suitable!’, ‘what is required!’; only in the 1850’s that it became widely used as an ordinary adjective, i.e. not necessarily in exclamations. It reached England about 1880 as slang; since the Great War it has ranked as a colloquialism.”
O.K.’s first written, testified use was by the Democrats during the presidential election of 1840. Their candidate, Martin Van Buren, had the nickname of “Old Kinderhook” (after his birthplace in New York state), and his supporters called themselves the “OK Club”.
In Britain in the early 1880s, the music hall artiste Alfred Glanville Vance (known as “The Great Vance”) used to perform a number called “Walking in the Zoo” written by Hugh Willoughby Sweny and composed by Alfred Lee. The song is said to have popularised both “O.K.” and “Zoo” (as a truncated form of Zoological Society of London):
“The Stilton, sir, the cheese, the O.K. thing to do,
On Sunday afternoon is to toddle to the Zoo.
Week-days may do for Cads, but not for me and you:
So dressed right down the road, we show them who is who.”
The audience was expected to sing along with the chorus:
“Walking in the Zoo, walking in the Zoo,
The O.K. thing on Sunday is the walking in the Zoo.”
The earliest known use of O.K. in print is said to have been on 23 March 1839 in an edition of the Boston Morning Post containing an announcement about a trip by the Anti-Bell-Ringing Society. As an early example of its use in literature the New Shorter Oxford English Dictionary cites the first line of the short story “Monkey Nuts” by D. H. Lawrence in England, My England (1922): “At first Joe thought the job O.K.”
Eric Partridge stated his own “very carefully considered” view of the origin of O.K. as representing:
“The Choctaw Indian oke (or hoke), ‘it is so’; that Jackson was the first to use the form O.K., for he almost certainly knew the Choctaw word; and that it was his opponents who, wishing to make electioneering capital out of his well-known illiteracy, foisted on him the legend that he employed O.K. as a convenient abbreviation of orl k’rect.”
Partridge notes that “O.K.” was made familiar to the public by the labels on Mason’s O.K. Sauce. Extremely popular in England during the first half of the 20th century, O.K. Sauce was later dropped by most major supermarkets – possibly in favour of HP Sauce – although it is still marketed in the Far East. Mason’s advertising often played on “sauce”, “saucy” and “sauciness” in the manner of British seaside postcards as in the naughty monks’ poster below.