Ok

In the 1830s, in Boston, there was a fad of making abbreviations; also of using jocular misspellings. So “all correct” became of “oll korrect” which became abbreviated to OK.


The word would have ended as a fad, but along came US President Martin Van Buren (1782-1862). 

During his re-election campaign of 1840, his supporters adopted the word OK as a nickname for him (short for Old Kinderhook; he was born in Kinderhook, New York)