Maneely then found work at publisher Martin Goodman's Marvel Comics predecessor, Timely Comics, as it was transitioning to its 1950s incarnation as Atlas Comics. His first published story there was the eight-page Western story "The Kansas Massacre of 1864" in "Western Outlaws And Sheriffs" #60 (Dec. 1949). However, historian Michael J. Vassallo, dating stories by Atlas' published job-numbers, suggests the first Atlas story to which Maneely contributed was the later-published "The Mystery of the Valley of Giants" in "Black Rider" #8 (March 1950), an 18-page story drawn by many uncredited artists, including Syd Shores; Maneely's work appears on page three, with some additional minor inking on five other pages.