Detail from cover of Zap Comix #2 (1968).
As children, these [creators] were the very people who had been worst hit by the 1950s scare — sometimes having their comics collections torn up by their parents, or thrown on the playground fires. Now it was time for payback: where the Code had stipulated "no violence," "no sex," "no drugs," and "no social relevance," the underground comix would indulge themselves to the maximum in every category.
— Roger Sabin, Comics, Comix and Graphic Novels: A History of Comic Art
While mainstream comics publishers were being stifled by the strictures of the Comics Code Authority, a countervailing movement was taking shape, inspired by Harvey Kurtzman's Mad magazine and cultivated by college student publications like the The Texas Ranger and Snide, as well as "alternative newspapers" such as The Barb, Yarrowstalks, and The East Village Other. Called "comix" to distinguish them from their mainstream counterparts, these works were influenced by hippie counterculture and were aggressively profane, unapologetically political and painfully unfiltered.
While there were a number of underground strips that appeared throughout the 1960s, the publication of Robert Crumb's anthology comic Zap in 1968 is usually cited as the true start of the movement, initiating an explosion of titles by artists like S. Clay Wilson, Gilbert Shelton, and "Spain" Rodriguez. The early 1970s saw the emergence of comix by and for women, including creators Willy Mendes, Lee Marrs and the "Queen of the Underground," Trina Robbins.
Unfortunately, in attempting to push the bounds of acceptability and good taste, comix creators were often unabashedly racist, sexist and homophobic. The works of Robert Crumb, the "father" of the underground, were "crowded with misogynist images, often involving violence. His excuse was that he was expressing his innermost feelings, as every artist has a duty to do" (Sabin, 1996, p.103). However, this was a less-then-acceptable answer to some female comix creators, whose work often focused on the "boys' club" nature of the scene and reactionary currents running through the supposedly-subversive medium:
I noticed the misogyny in the comics and spoke up. Of course as soon as I would say, "But rape and torture and killing women isn’t funny," the guys would go, "You have no sense of humour."
— Trina Robbins, "An Interview with Comics Artist, Writer, and 'Herstorian' Trina Robbins"