How the word “OK” was invented?

O in English slang means zero, K is short for kills. In some wars soldiers used to say 0 Kills by using the term OK. 

How the Word “OK” Was Invented Years Ago

In, abbreviations were all the rage (think LOLZ, OMG or NBD today). "This trend," Good continues, "produced many unsuccessful terms such as OW—an OK-like term for “oll wright” (all right) that flopped.

OK first appeared as an abbreviation for “Oll Korrect,” printed in a satirical article about grammar, the Economist continues. The word's origins were only revealed in thes, however, when etymologist Allen Read did some digging—through suggestions that the word might come from Europe, a Civil War nickname for biscuits, or an abbreviation for the telegraph term Open Key. 

Still others falsely thought that president Martin Van Buren had invented the term in his presidential campaign, which used the slogan "Vote for OK" in reference to both his hometown and his nickname, Old Kinderhook. But Van Buren only popularized the term, Read found, not invented it. 

Although Read showed "how, stage by stage, OK was spread throughout North America and the world to the moon, and then took on its new form AOK, first used by space people and frowned on by purists,", some doubters continue to insist that the word in fact has a much earlier origin. We'll just have to be OK with never knowing for absolute sure. 

it is an abbreviation of the word"oll korrect" printed in a satirical article,its origin was revealed in the 1960th then it was used as a slogan 'vote for ok' after it was used everywhere as 'open the key'.it was spread to North America and then took the form as AOK.purists ,economists and doubters finished their use of the word till it becomes OK.

There are many rumors about the origin of this word, including:

- It represents the first votes of the total All correct

- It is linked to an electoral event was one of the contestants name begins with the letter O and the other starts with the letter K

- That in World War II meant "zero killed" is said when there are no injuries, shortened "0k" meaning that everything is okay.

- Obediah Kelly's theory: It is said that a man who works as an agent in charge Railway, and it was to write and sign the shipping documents that have been selected and accepted. Ok it became shorthand for the name, and became the show approval and acceptance.

- Theoretical derivation of other languages: Here are some shows that ok derived from several languages, and some shows that ok derived from the Scots who use the term "och aye", and the French "aux Cayes", and much of what mentioned in oxford.

- Encyclopaedia Britannica said that the origin of this word was in the United States, and of them went out to the world to subsequently become a global word all levels, especially at the global level.

Thanks to the answers of the experts !!!

I agree with M's Ghada answers, thanks. 

Thank you for inviting ..... Support answer dalal answer very good

I agree with Ms.Dalal ansnwer, I did some online search but didn't get to the real origin of the word.

good to know about that .......................................

VOTE for Old Kinderhook Please refer to below link 

https://www.google.com.sa/search?q=ok+invention&oq=ok+inv&gs_l=serp.3.1.0l3j0i22i30l7.1761.6309.0.8602.6.6.0.0.0.0.158.892.0j6.6.0....0...1c.1.64.serp..0.6.890.0QrZZ2BA-c4

zero killing

and other by vote in old