Captain Marvel (DC Comics) abilities. Based on book sales, the character was the most popular superhero of the 1940s, outselling even Superman. Fawcett expanded the franchise to include other "Marvels", primarily Marvel Family associates Mary Marvel and Captain Marvel Jr., who can harness Billy's powers as well. Captain Marvel was also the first comic book superhero to be adapted into film, in a 1941 Republic Pictures serial titled "Adventures of Captain Marvel". Fawcett ceased publishing Captain Marvel-related comics in 1953, partly because of a copyright infringement suit from DC Comics, alleging that Captain Marvel was a copy of Superman. In 1972, DC licensed the
Captain Marvel (DC Comics) with "Justice League" #21, preceding DC's crossover storyline "Trinity War" which heavily features the Shazam mythos. Johns and Frank's reboot was met with both acclaim and criticism, and the renaming of the hero as Shazam brought mixed reactions. Johns noted that the change was made "because that's what everyone thinks his name is anyway," due to the inability to use the "Captain Marvel" moniker on comic book covers and merchandise. In updating "Shazam!," Johns and Frank skirted some controversy among long-time fans by introducing Billy Batson as a cynical foster child who comes to appreciate his potential as a hero