 Republic previously had adapted Fawcett Comics characters (Captain Marvel and Spy Smasher).Due to the fact that the lead in "Captain America" is a crime-fighting district attorney aided by a female secretary who knows his identity, and that the serial includes a chapter entitled "The Scarlet Shroud" in which nothing scarlet appears, film restoration director Eric Stedman suggests that it is more likely that the script was originally developed to feature Fawcett's comic book hero Mr. Scarlet, secretly D.A.Brian Butler, whose comic book appearances had proved unpopular and who had actually disappeared from comic book covers and been relegated to being a backup feature between the time the serial was planned and the final film produced.