Most people all over the world, even if they do not understand English, understand and use the American expression “OK.” Nobody knows for sure exactly where or when that expression became part of our language, but there are several possible sources that are accepted.
Some believe that “OK” may have come from the Choctaw Indian word okeh, which means “it is so, and no other way.”
Others believe that the expression originated with Andrew Jackson, the 7th president of the United States. Jackson was considered one of the least educated of all the American presidents, having left school at the age of 13 to fight in the Revolutionary War.
The story goes that Jackson thought “OK” was an abbreviation of “Oll Kurrect,” which was his spelling of “All Correct.”
I heard once that the expression “OK” came from World War 1.
The American Troups had a board where they used to write the number of casualties they had each day. i.e. 0 Killed.
A little later, they started using “0 K, short for “zero killed”, as a phrase meaning everything had gone all right that day.
O.K/Okay comes from the scots “och aye” and various mispronunciations after.
The saying “O.K.” may have come from president Martin Van Buren who was nicknamed Old Kinderhook. Kinderhook is the town Martin grew up in as a child, and thus ended up named Old Kinderhook. For his reelection, in 1840, Martin’s campaign advertisement was “O.K” he often would say “I’m “O.K”, You’re “O.K”.”
I heard that too, recently. I believe it to be the truth, rather than a crazy story about Prez Jackson or some Indian sayings.
I was told as a boy “OK” came to be after a man called Oskar Krause, sorry about the surname spelling but that’s how it sounds, signed off Henry Fords Model T’s with “OK” in white chalk under a mudguard to show he had checked and the vehicle had passed his inspection.