Before okay entered common usage, what did people commonly say to denote “approval, acceptance, assent, or acknowledgment”?
(I lifted that phrase from Wikipedia, hence the quotation marks)
“All right.”
“Certainly.”
“I agree” or “Agreed.”
“Surely.”
“Indeed.”
And of course…
“Yes.”
But was there a single go-to word, like “okay,” that people used before “okay” became popular?
Aye.
Yup. 
I believe it was “Okely-Dokely”.
mmm
“That’s a fact, Jack!”
Yer dern tootin’!
In sooth.
Verily.
Most assuredly.
Yea.
True dat
As you wish
Yah, sure, you betcha!
Right you are, then.
Is there anything “ok” does that “all right” doesn’t?
(Particularly given that “ok” is supposed to have come from “oll korrect” [is that still the accepted etymology? It sounds so crazy…], which is almost the same phrase as “all right”)
Righty-Oh
At Renaissance Faire language classes, we’re told to substitute “Well enough” (Prononuced “Well Enow”) for “OK.”
That sounds etymologically backwards to me. The reason that gh sounds like an F is because the CH was hard to say. Surely it should be “Well Enowch”
(CH means , German loch)
“Word.”
There isn’t a single go-to word today, is there?