The first issue of Zap was published in San Francisco in early 1968. It featured the work of satirical cartoonist Robert Crumb. While a few small-circulation self-published satirical comic books had been printed prior to this, Zap #1 became the model for the "comix" movement that snowballed after its release. (Another all-Crumb issue of Zap was drawn before issue one, but was not printed earlier because of problems with a publisher. That issue subsequently appeared as Zap #0.)
After the success of the first issue, Crumb opened the pages of Zap to several other artists, including S. Clay Wilson, Robert Williams, "Spain" Rodriguez, and two artists with reputations as psychedelic poster designers, Victor Moscoso and Rick Griffin. This stable of artists, along with Crumb, remained mostly constant throughout the history of Zap, which published sporadically until 1998 (Zap #14). Griffin died in 1991; a two-page story by artist Paul Mavrides appeared in the final issue. Mavrides was invited to contribute when Crumb announced that he no longer wanted to work on Zap.
While the origin of the spelling "comix" is a subject of some dispute, it was popularized by its appearance in the title of the first issues of Zap. "Zap" was also one of the books that put the "underground" in comics: Zap #4, in particular, was the subject of numerous obscenity busts and court cases.