The term "beat generation" was introduced by Jack Kerouac in approximately 1948 to describe his social circle to the novelist John Clellon Holmes (who published the first novel of the beat generation, titled Go, in 1952, along with a manifesto of sorts in the New York Times Magazine: "This is the beat generation"). The adjective beat (introduced by Herbert Huncke) had the connotations of "tired" or "down and out", but Kerouac added the paradoxical connotations of "upbeat" and "beatific".
Calling this relatively small group of struggling writers, artists, hustlers and drug addicts a "generation" was to make the claim that they were representative and important—the beginnings of a new trend, analogous to the influential Lost Generation. This is the kind of bold move that could be seen as delusions of grandeur, aggressive salesmanship or perhaps a display of perceptive insight. History shows it was clearly not just a delusion, but possibly a real insight into some real trends that became self-reinforcing: the label helped to create what it described.
The members of the beat generation were new bohemian libertines, who engaged in a spontaneous, sometimes messy, creativity. The beat writers produced a body of written work controversial both for its advocacy of non-conformity and for its non-conforming style.
The canonical beat generation authors met in New York: Jack Kerouac, Allen Ginsberg, William Burroughs, (in the 1940s) and later (in 1950) Gregory Corso. In the mid-50s this group expanded to include San Francisco area figures such as Kenneth Rexroth, Gary Snyder, Lawrence Ferlinghetti, Michael McClure, Philip Whalen and Lew Welch.
Perhaps equally important were the less obviously creative members of the scene: Lucien Carr (who introduced Kerouac, Ginsberg and Burroughs); Herbert Huncke a drug addict and petty thief met by Burroughs in 1946; Hal Chase, an anthropologist from Denver who in 1947 introduced into the group Neal Cassady. Cassady was immortalized by Kerouac in the novel On the Road (under the name "Dean Moriarty") as a hyper wildman, frequently broke, largely amoral, but frantically engaged with life.
Cassady introduced into the beat scene the "rap"; the loose spontaneous babble that later became associated with "beatniks". Cassady was not much of a writer himself, though the core writers of the group were impressed with the free-flowing style of some of his letters, and Kerouac cited this as a key influence on his invention of the spontaneous prose style/technique that he used in On the Road (the other obvious influence being the improvised solos of Jazz music).
All of this does not yet mention the oft-neglected women in the original circle, such as Joan Vollmer and Edie Parker. Their apartment in the upper west side of Manhattan often functioned as a salon and/or crash-pad, and Joan Vollmer in particular was a serious participant in the marathon discussion sessions.
In 1950 Gregory Corso met Ginsberg, who was impressed by the poetry Corso had written while incarcerated for burglary. Then during the 1950s there was much cross-pollination with San Francisco area writers (Ginsberg, Corso, Cassady and Kerouac all moved there for a time). Ferlinghetti (one of the partners who ran the City Lights press and bookstore) became a focus of the scene as well as the older poet Rexroth, who's apartment became a Friday night literary salon. Rexroth organized the famous Six Gallery reading in 1955, the first public appearance of Ginsberg's poem Howl.
When On the Road was finally published in 1957 (it had been written in 1951), it received a strong review in the New York Times Book Review and became a best-seller. This produced a wave of fame that all of the beats from then on had to surf on or drown under.
The term "Beatnik" was coined by Herb Caen of the San Francisco Chronicle on April 2, 1958 as a derogatory term, a reference to the Russian satellite Sputnik, which managed to suggest that the beats were (1) "way out there" and (2) pro-Communist. This term stuck and became the popular label associated with a new stereotype of men with goatees and berets playing bongos while women wearing black leotards dance.
A classic example of the beatnik image is the character Maynard G. Krebs played by Bob Denver on the Dobie Gillis television show that ran from 1959 to 1963.
In the popular television cartoon show, The Simpsons, the parents of Ned Flanders are beatniks.