There have certainly been efforts to draw arbitrary distinctions between groups based on speech for a very long time, probably going almost as far back as language itself.

What I was referring to was specifically an effort rooted in a desire to use rules of Latin grammar to restrict constructions in English. This was a big thing relatively recently (likely sometime in the past 100-300 years). It is this movement from which we get rules like "never end a sentence with a proposition" or "don't split infinitives" --- those sorts of things.