I picked up a couple of underground magazines - well they were probably ground-level for the time - that are going to be passed along to MSU's Comic Art Collection soon. Before I do that, here's some of the more famous underground cartoonists from Apple Pie May 1975.
Neal Adams art on this.
Terry Austin, the great inker, apparently did editorial cartoons too.
A couple of one-pagers by Justin Green.
Paul Kirchner did the surrealist strip The Bus for alternative weekly newspapers, until I seem to remember that he came into money - Ninja Turtle money maybe?
And a three-page strip by Kirchner: