Zap Comix has been published since 1968.
Notes on verification
Multiple independent sources (Wikipedia, Grand Comics Database, Fantagraphics) confirm 1968 as the start of publication, with minor nuance about copyright vs. release dates that doesn't affect the core claim.
Sources
- Robert Crumb – Der Schmutzfink (blog.dnb.de)
- https://www.comics.org/issue/21551/ (comics.org)
- https://www.fantagraphics.com/collections/zap-comix (fantagraphics.com)