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 Jr. of World War II-era comic stories. Immediately following the crossover chapters in "Master Comics" #21–22, Captain Marvel Jr. began starring in the series with issue #23 (February 1942). His own "Captain Marvel Jr." comic book launched nine months later. Mac Raboy's darker, more dramatic art style illustrated adventures with more serious themes than those often seen in the often whimsical Captain Marvel stories. Marvel Jr's regularly dealt with espionage, organized crime, murder, and Nazis in more-or-less straightforward adventure styles with often somber overtones. The stories depicted the plight of working class and working poor people during World War II. Even