How did newspaper comic strips lead to the development of superhero comic books?

Superheroes are an outgrowth of newspaper comic strips, which served as the primary vehicle for the evolution of the comic book format.1

The transition occurred through several key developments:

• Format Evolution: Early comic books, such as Famous Funnies (1934), began as anthologies of reprinted newspaper strips. As the demand for adventure stories grew, publishers transitioned from reprinting existing strips to producing original material.23
• Convergence of Media: By the 1930s, the comics page expanded to include continuous-action adventure strips, such as Tarzan and Flash Gordon, which utilized cinematic techniques and realism. These adventure-oriented strips, alongside the influence of pulp magazines featuring mysterious heroes, provided the narrative foundation for the superhero genre.342
• The Superhero Prototype: While creators like Jerry Siegel and Joe Shuster initially attempted to sell Superman as a daily newspaper strip, the character eventually debuted in Action Comics #1 in 1938. The massive success of this title established the superhero formula—a costumed hero with an altruistic mission and superpowers—which was then widely imitated in the burgeoning comic book industry.43