Origins of 'OK'

From the Freakonomics Blog:

The phrase “OK” is everywhere, but where did it get its start? A new booktackles its history, and NPR interviews the author, Allan Metcalf. The phrase originated with a few newspaper editors in 1839. “They had a lot of abbreviations that they were using and made up on the spot and thought they were terrifically funny,” says Metcalf. “And OK was an abbreviation for ‘All Correct.’” The phrase gathered momentum during the 1840 re-election campaign of Martin Van Buren. “He got the nickname Old Kinderhook, and early in 1840, OK clubs sprung up with the slogan, ‘OK is OK.’ So taking that funny little word and making it a mainstay of the political conversation in 1840, suddenly OK was way OK.” All right then.