♪ OK. ♪

♪ OK. ♪

♪ OK, are you OK, Annie? ♪

♪ OK, OK, OK, OK ladies... ♪

OK might be the most recognizable word on the planet.

- OK! - OK.

It's essential to how we communicate with each other and even with our technology.

Alexa, turn off the living room light.

OK.

You probably use it every day, even if you don't notice it.

But what does OK actually mean?

And where did it come from?

- Uh, OK. - OK, then.

OK, thank you.

"OK" actually traces back to an 1830s fad of intentionally misspelling abbreviations.

Young intellectual types in Boston delighted those in the know with butchered coded messages such as KC, or "knuff ced"; KY, "know yuse"; and OW, "oll wright".

But thanks to a couple of lucky breaks, one abbreviation rose above the rest: OK, or "oll korrect".

In the early 1800s, "all correct" was a common phrase used to confirm that everything was in order.

Its abbreviated cousin started going mainstream on March 23, 1839, when OK was first published in the Boston Morning Post.

Soon, other papers picked up on the joke and spread it around the country, until OK was something everyone knew about, not just a few Boston insiders.

And OK's newfound popularity even prompted a flailing US president from Kinderhook, New York, to adopt it as a nickname during his 1840 reelection campaign.

Van Buren's supporters formed OK Clubs all over the country, and their message was pretty clear: Old Kinderhook was "oll korrect".

The campaign was highly publicized and turned pretty nasty in the press.

His opponents ended up turning the abbreviation around on him, saying it stood for "orful konspiracy" or "orful katastrophe".

In the end, even a clever nickname didn't save Van Buren's presidency.

But it was a win for OK.

That 1840 presidential campaign firmly established OK in the American vernacular.

And while similar abbreviations fell out of fashion, OK made the crossover from slang into legitimate, functional use, thanks to one invention: the telegraph.

If we lower the bridge, the current flows to the sounder.

At the other end, the current energizes an electromagnet and this attracts the armature.

The armature clicks down against a screw and taps out a message.

The telegraph debuted in 1844, just five years after OK.

It transmitted short messages in the form of electric pulses, with combinations of dots and dashes representing letters of the alphabet.

This was OK's moment to shine.

The two letters were easy to tap out and very unlikely to be confused with anything else.

It was quickly adopted as a standard acknowledgement of a transmission received, especially by operators on the expanding US railroad.

This telegraphic manual from 1865 even goes as far as to say that "no message is ever regarded as transmitted until the office receiving it gives OK".

OK had become serious business.

But there's another big reason the two letters stuck around, and it's not just because they're easy to communicate.

It has to do with how OK looks.

Or, more specifically, how the letter K looks and sounds.

It's really uncommon to start a word with the letter K in English ⏤ it's ranked around 22nd in the alphabet.

That rarity spurred a "Kraze for K" at the turn of the century in advertising and print, where companies replaced hard Cs with Ks in order to "Katch" your eye.

The idea was that modifying a word, like "Klearflax" Linen Rugs or this "Kook-Rite" Stove, for example, would draw more attention to it.

And that's still a visual strategy: We see K represented in modern corporate logos, like Krispy Kreme and Kool-Aid.

It's the K that makes it so memorable.

By the 1890s, OK's Bostonian origins were already mostly forgotten, and newspapers began to debate its history, often perpetuating myths in the process that some people still believe.

Like the claim that it comes from the Choctaw word "okeh", which means "so it is".

♪ Choctaw gave us the word OK; va... ♪

OK's beginnings had become obscure, but it didn't really matter anymore; the word was embedded in our language.

Today, we use it as the ultimate "neutral affirmative".

OK, then.

OK, then.

- Learn to truly love yourself. - OK.

OK, get yourself up here!

OK!

I don't know what to say.

Say "OK".

OK.

It's settled, then.

Allan Metcalf wrote the definitive history of OK, and he explains that the word "affirms without evaluating", meaning it doesn't convey any feelings, it just acknowledges and accepts information.

If you "got home OK", it just means you were unharmed.

If your "food was OK", then it was acceptable.

And "OK" confirms a change of plans.

It's sort of a reflex at this point; we don't even keep track of how much we use it.

Which might be why OK was arguably the first word spoken when humans landed on the moon.

Not bad for a corny joke from the 1830s.

All right, guys, cut it out.