Every day people use the word 'OK'. But where did it come from? In truth, no one really knows for sure, but there are several different theories as to where it originates.
The theory that is widely recognised by most dictionaries is that 'OK' is an abbreviation for 'oll korrect', a humorous play on the words 'all correct'. In the early 19th Century, newspapers did not just feature serious news; they also had lots of humour and fiction. Humourists liked to deliberately misspell words. For example, they would spell words like 'no' as 'know'. It was also a fad back then to use abbreviations. So a misspelled 'oll wright' (all right) could become 'OW'. And the first known printing of the word 'OK' was in the newspaper the Boston Morning Post on 23 March, 1839, in this context: 'He of the Journal, and his train-band, would have the "contributions box", et ceteras, o.k. - all correct - and cause the corks to fly.' And thus, it is assumed that 'OK' was a play on the words 'all correct'.
The term 'OK' was only popular for a while. Eventually it disappeared. But it was later revived when the Democrats in New York, USA sponsored their candidate, Martin Van Buren. Because Buren was from Kinderhook, New York, his nickname was 'Old Kinderhook', which was abbreviated 'OK'. They started a 'Democratic OK' club and used the term 'OK' as a catchphrase.
Another theory that surrounds 'OK' is that US President Andrew Jackson used it to approve legal documents. Jackson was not a good speller and 'ole korreck' was supposedly how Jackson spelled 'all correct'. When journalists heard about this, they wrote many stories about it in the newspapers. This is how 'OK', Andrew Jackson, and 'all correct' became fixed in American Folklore.
The term 'OK' was used many, many times in newspapers, until the real origins of the word were forgotten, except the Andrew Jackson tale. In the newspapers, people would send in what they thought the origin of 'OK' was. Even words in other languages were suggested. One of the more popular suggestions was that 'OK' came from the Choctaw1 word 'okeh'. The OED (Oxford English Dictionary) says that 'okeh' means 'it is' and that it may have come from the French words 'au quai', or from the West African language Wolof via slaves from the Southern States.
There are several other stories regarding 'OK'. One was that a painter named Oscar Kokoschka signed his work with a large 'OK'. Another is that it is an inversion of 'KO' - as in the boxing term, 'knock-out'. Also, it is rumoured to have been used in the American Civil War - standing for 'zero kills'. Or perhaps it was used in the 19th Century for telegraphic communication, supposedly standing for 'Open Key'.
A more recent legend is that a man in a Ford car factory, named Oscar Kolle, that had the job of making sure all the parts being manufactured were good. If the item passed his 'quality assurance' test, then he would put his initials, 'OK', on the part.
And so, as the years went on, and people used 'OK' more and more often, its true origin shrank back into the fog of time once more. Maybe one day the origin will be found. Or maybe not. Only time will tell.