In 1950, he joined the United Feature Syndicate and took over the Tarzan comic strip. In 1954, he began working with Al Capp, and in 1959 took over The Saint comic strip before jumping to King Features in 1960. At this point, he began drawing Secret Agent X-9 under the name of "Bob Lewis", and was succeeded by Al Williamson in 1967. In 1970, he began working with Al Capp again on the Li'l Abner comic strip before joining Marvel Comics in the late 1970s. In the early 1980s, he joined DC Comics, and while there, inked over Joe Brozowski's pencils on several covers for their Star Trek title, taking credit as "Bob Lewis" once again.