A “bumpkin” is an unsophisticated or socially awkward person from the countryside; a yokel, a hayseed, a hick. There are many words to indicate the dim-wittedness of rustics but few to suggest their intelligence. Obviously it’s meant to be insulting.
A “bumpkin” was originally, in the 1500s, a name the English used for the Dutch, whom they portrayed as small, comic, and tubby. The word arises from either the Dutch boomken, meaning “little tree” or bommekijn, meaning “little barrel.” Back then, the British and the Dutch were less than friendly, as they sparred over trade routes and political boundaries.
By the 1700s, “bumpkin” just meant “stupid fellow.”
The British didn’t need slang terms for rustics from Holland; they had their own “yokels.” “Yokel” was derived as a name for an ignorant rustic from the old dialect name for a green woodpecker. An early example of it in print is found in the Morning Post, May 1820.
Meanwhile, in America, hicks were rising in the fields. Actually, although “hick” is now a bona fide American term, it originated in the UK. It came about via the habit of changing the first letters of names in order to make a diminutive nickname. Robert became Bob, William became Bill and Richard became Dick or Hick. The British publication A New Dictionary of the Terms Ancient and Modern of the Canting Crew, 1699, defines “Hick” thus: “A silly Country Fellow.”
“Hayseed” is another term for a rustic. It was coined by author Herman Melville, in Moby-Dick, 1851, in a sequence where he suggests that a “country-bred… downright bumpkin” would fare badly in a storm at sea: “Ah, poor Hay-Seed! how bitterly will burst those straps in the first howling gale.”
Another US term is “hillbilly.” The New York Journal in April 1900 defined it thus: “A Hill-Billie is a free and untrammelled white citizen of Alabama, who lives in the hills, has no means to speak of, dresses as he can, talks as he pleases, drinks whiskey when he gets it, and fires off his revolver as the fancy takes him.”
As a genuine, card-carrying stubble-jumper myself, I’m inclined to think that city slickers are just jealous of our freedom. Though I doubt the RCMP would take kindly to me firing off a revolver whenever I felt like it.