The golden age is popularly considered to have begun in 1938 with the debut of Superman in Action Comics #1, published by DC Comics. Superman was so popular that superheroes soon dominated the pages of comic books.
The golden age arguably ended in 1951 when the title All-Star Comics ceased to chronicle the adventures of the superhero team the Justice Society of America and changed its name with #58 to All-Star Western. This marked the decline of superheroes in the medium and the 1950s marked a major slump in comics popularity.
The most popular character during the golden age was Captain Marvel by Fawcett Comics. One of the most acclaimed series artistically was The Spirit by Will Eisner.
See also: Silver Age of Comic Books