Reed Crandall and inked by Williamson. From 1955 to 1957, Williamson produced over 400 pages of three-to-five-page stories for Atlas Comics, the 1950s forerunner of Marvel Comics, working in various genres but primarily Westerns. He continued to collaborate with Torres and Krenkel, as well as with Gray Morrow, George Woodbridge and Ralph Mayo. With Mayo, one of the first editors to give Williamson work, at Standard Comics, Williamson collaborated on the jungle girl series Jann of the Jungle #16–17 (April and June 1957). Following Mayo's death, Williamson drew stories solo for the planned #18, but the series was abruptly canceled before that issue could be published. His "prolific though somewhat uneven two-year stint at Atlas", where he first drew war comics, yielded superlative art in such stories as "The City That Time Forgot", in Marvel Tales #144 (March 1956); "Menace from the Stars", in Mystery Tales #44 (Aug. 1956); "The Unknown Ones", in Astonishing #57 (Jan. 1957); "Dreadnaught", in Navy Tales #2 (March 1957); and "Helpless", in Battle #55 (Nov. 1957). While "something appeared to be missing from a lot of his Atlas work: enthusiasm," Williamson's Atlas Westerns, at least, "form a strongly consistent body of work, characterized by minimal to nonexistent action, a preponderance of closeups and reaction shots, and well-defined figures set against sparse backgrounds." From 1958 to 1959 Williamson worked for Harvey Comics collaborating with former EC artists Reed Crandall, Torres and Krenkel and inking the pencils of Jack Kirby (for Race to the Moon #2–3 and Blast-Off #1). On inking Kirby, Williamson relates: "I remember going up to Harvey and getting work there. They said, 'We haven't got any work for you, but we have some stories here that Jack penciled. Do you want to ink them?' I'd never really inked anybody else before, but I said, 'Sure,' because I looked at the stuff, and thought, I can follow this, it's all there. I inked it and they liked it, and they gave me three or four stories to do." Additionally, Williamson drew stories for Classics Illustrated (in collaboration with Crandall and Woodbridge); Canaveral Press's line of Edgar Rice Burroughs books (inked by Crandall); Westerns for Dell Comics (including Gunsmoke #8–12) and Charlton Comics, including two complete issues of the Cheyenne Kid, (#10–11) with Angelo Torres, and science-fiction stories for ACG, including "The Vortex", in Forbidden Worlds #69 (1958). He also worked with former EC artist