One of the few (only?) genuine pre-20th century acronyms in English is Smectymnuan, listed in the OED.
It’s an adjective formed from Smectymnuus, the title of a 17th century religious polemic formed from the initials of its authors, the Puritan divines Stephen Marshall, Edmund Calamy, Thomas Young, Matthew** N**ewcomen and William Spurstow.
Here’s an example of its (extremely limited!) use:
In May 1641 he put forth a defense of the Smectymnuan side in Of Reformation touching Church Discipline in England and the Causes that hitherto have hindered it.
I think that’s a good idea, and I’m sorry I didn’t catch it sooner (instead, I helped the hijack along.) When someone does start such a thread, please email me and I’ll provide a link to it in this thread, but we probably should hold this thread pretty much to the Staff Report on “cop.”
If this is all true, you have to wonder who came up with it, and how long he spent screwing around with the initials until he got something pronounceable.
Imagine if the committee itself did it:
Thomas Young: Well, I say I should be first. Then it could be Tymnecsmium
Stephen Marshall: No, that sounds silly. I should be first – Smect…
Edward Calamy: I want to be first
Others: No!
TY: You have to be in the middle, Ed. Nobody else has a vowel for their first name.
William Spurstow: I don’t like any of these. I keep getting stuck at the end, and you change my initials anyway
Not quite an acronym, but there was the Cabal ministry in the 1670s in England. The word “cabal”, meaning a conspiratorial group or scheme, was a well-known word prior to the Cabal Ministry forming, but the intials of the five principals in the Ministry could be arranged to spell “Cabal”, so their political opponents used it to suggest that they were taking over the government.
It’s not that people never used acronyms in the past, it’s just that with the exception of OK none of them lasted in general use. In fact, OK was just one of a multitude of similar joking abbreviations going around at the time. All the others have long been forgotten, though.
Not just that region and time. It was common in my youth in the 60s in Southern England and is still in use today. It dates back to at least the 1880s.
OED says, “Various suggestions have been made as to the etymology of this word, including a shortening of the name of Sir Robert Peel (see peeler n.3 and compare bobby n.), or derivation from either French rousse (1827) or roussin (1811), both in the sense ‘policeman’ and of unknown origin.”.