Under the G.I. Bill, Maneely trained at the Hussian School of Art in Philadelphia. He entered the professional realm in the advertising art department of the "Philadelphia Bulletin" newspaper. He began his comic book career freelancing for Street & Smith in 1948, drawing such features as "Butterfingers", "Django Jinks, Ghost Chaser", "Dr. Savant", "Mario Nette", "Nick Carter", "Public Defender", "Roger Kilgore", "Supersnipe", and "Ulysses Q. Wacky" in comics including "The Shadow", "Top Secrets", "Ghost Breakers" and "Super Magician Comics". His earliest known credits are that company's "Top Secrets" #4 (Aug. 1948), for which he penciled and inked the eight-page crime fiction story "The Ragged Stranger"; and "Red Dragon" #4 (Aug. 1948), for which he drew the eight-page story "Death by the Sword" and the one-page featurette "Tao's Small Sword Box", both starring the hero Tao Anwar.