Camp as an artistic noun and verb, comes from the traditions of the British Royal Army, where soldiers in camp entertained themselves with satirical sketches often involving re-creations of movie and literary scenes and impersonation of officers, celebrities and women. Queer theorist Samuel R. Delany believes that this is a survival of times past when army encampments would employ female impersonators who performed for and sexually serviced the men, but there is no hard evidence to support this, and women would have been easier to come by. Anyway, by the Second World War, 'camping' had evolved from mere "there ain't nuttin' like a dame", "What would Clark Gable do?" and boneheaded CO jokes into a finely honed satiric tradition of over-the-top outrageousness, related to the 'skits' in Classic Scouting.
The one unbreakable rule was that you must only make fun of things, people, and places you genuinely admired, or would otherwise take quite seriously: a Rita Hayworth fan might come up with a sketch re-creating "Put the blame on Mame", or a patriotic soldier, Winston Churchill trying to woo Eleanor Roosevelt during Yalta. In this light, being a homosexual wouldn't be considered funny, but pretending to be one would be: "Ah, when I look into your eyes, I see the light of signal flares...Elope with me, Derek, and I'll show you the world!"
This would have remained unremarked upon and unremarkable, save for one Christopher Isherwood, who found the sketches very like the cabaret performances of Weimar Berlin in their stylization and humor. In his novel The World in the Evening, he described how 'camp' could describe such things as Baroque Catholicism, cartoons, and opera: "it isn't really making fun of something, it's making fun with something." he remarked. He distinguished further "high camp" (such as Noel Coward plays, where the stylization and humor is self-conscious, and willed) and "low camp" (such as say, Plan 9 From Outer Space, where the humor is unconscious and accidental). Even this didn't cause too much of a stir, until the young Susan Sontag published her "Notes on Camp" in 1964, touching off a pop phenomenon.
It bears explaining that the cultural world of the postwar era was at first a very serious one. Nowadays, the idea of academics studying rap lyrics as poetry and respected artists painting pictures of gum wrappers and gas stations is thoroughly humdrum: high and low culture meet all the time, and irony is such common currency in the Western world that it's hard to imagine any Western sacred cow (including the fact that some might find the term as being Orientalist) that hasn't been expertly butchered, barbecued and served with A-1 sauce. But in the Forties and Fifties, this was not so: the goal in cultural affairs then was to be taken seriously, as an adult, and the bar was set very high. One shibboleth of serious adulthood was to reject popular culture outright: while it was conceded that one might, with reservations, watch TV (particularly Omnibus or public broadcasting), go to a movie (particularly foreign films), listen to show tunes (particularly those by Leonard Bernstein or George Gershwin) or read a mystery novel (particularly if it was written by Simeon or Agatha Christie) now and then, the proper attitude of a serious adult towards pop culture, especially American pop culture, ranged from polite distaste to outright hatred and fear. No matter how ugly modern art could be, held common wisdom, how hard Schoenberg could be on the ear, how jarring Abstract Expressionism could be on the eye, how incomprehensible Finnegans Wake be to the mind, it was still better than the coldly manufactured vulgarity that passed itself off as American pop culture. In fact, the mere fact that these things were difficult to understand was proof that they were "better", the way a good Scotch was better than Coca-cola.
I give you this lengthy digression in order to stress to you exactly how strange it was when Ms. Sontag -- a woman of all things, wrote, in kitchen-clean academic prose, so dispassionate as to sound almost oracular, how it was completely OK to like ... King Kong? Flash Gordon? Pornography? To say "It's so bad it's good"? "The dandy held a perfumed handkerchief to his nostrils and was liable to swoon; the connoisseur of Camp sniffs the stink and prides himself on his strong nerves." It's as if art, locked into a search for ever-more recherche pleasures, had finally caught up with itself: if learning to appreciate the true beauty behind the ugliness of say, a painting by Francis Bacon was to progress as an art lover, then what would keep you from appreciating the technical accomplishment and beauty of a comic book?
I confess to knowing and liking her essay for at least twenty years before looking up the Isherwood quote, and finally understanding what she was trying to say. Divorced from any experience of Camp as a military/hetero phenomenon, Sontag stressed camp as a largely homosexual aesthetic, strongly urban in nature, more related to fashion photography than to pantomime. However, her remarks serve to differentiate Camp from kitsch, which is not at all the same (Precious Moments figurines aren't Campy, and Erte gouaches aren't kitsch).
Within a year of her essay being published, it was hip to like Art Nouveau, Rudolf Valentino and Theda Bara, science fiction and that new thing, Pop Art. In 1966, it seemed as if comic books had taken over the media with a musical based on Superman on Broadway and Batman invaded the airwaves with a totally irreverent (but thoroughly gay-friendly) TV series. (Pontificate on the Dark Knight all you like, but the 60's series had the nerve to feature G. David Schine in a cameo. You just can't make these things up.) Not only did people make fun of...oh, sorry with commercials, but people even wrote songs about them -- listen to "(I Can't Get No) Satisfaction" sometime. Things really haven't been the same since.