After graduating from high school in Aurora, Colorado, Campbell began doing freelance commercial art jobs. As Campbell prepared to show his samples at the 1993 San Diego Comic Con, the series "WildC.A.T.S" premiered by Jim Lee's publishing studio, Wildstorm Productions (then called Homage Studios). One issue advertised a talent search for which readers could submit artwork, so Campbell put together a package that included a four-page "WildC.A.T.S" story and sent it in. A week and a half later, Jim Lee telephoned Campbell and asked him if he would move to San Diego to work for him. Initially working under the professional name Jeffery Scott, Campbell's first comics work was two pinups for the Homage Studios "Swimsuit Special" in 1993. His subsequent work for Wildstorm includes spot illustrations in "WildC.A.T.S Sourcebook". and "Stormwatch" #0.