American comic book Kane and Bill Finger created Batman, who debuted in "Detective Comics" #27 (1939). The period from the late 1930s through roughly the end of the 1940s is referred to by comic book experts as the Golden Age of comic books. It featured extremely large print-runs, with "Action Comics" and "Captain Marvel" selling over half a million copies a month each; comics provided very popular cheap entertainment during World War II especially among soldiers, but with erratic quality in stories, art, and printing. In the early 1940s over 90 percent of girls and boys from seven to seventeen read comic books.
American comic book tropes North America. There are many definitions of a superhero, and the subject is debated by scholars and industry professionals. Peter Coogan identifies influences to comic book superheroes in the form of super-strong comic strip characters, pulp heroes, masked vigilantes dubbed "mystery men", and precursors, who lack specific elements of modern superhero convention. According to Coogan, Superman is the first character to bring together all of the necessary elements. Coogan defines the superhero as "a heroic character with a selfless, pro-social mission" who has powers, a codename, colorful costume, and usually a secret identity. American comic books can be sold through