Superman of the Übermensch; they never acknowledged as much. Since 1938, Superman stories have been regularly published in periodical comic books published by DC Comics. The first and oldest of these is "Action Comics", which began in April 1938. "Action Comics" was initially an anthology magazine, but it eventually became dedicated to Superman stories. The second oldest periodical is "Superman", which began in June 1939. "Action Comics" and "Superman" have been published without interruption (ignoring changes to the title and numbering scheme). A number of other shorter-lived Superman periodicals have been published over the years. Superman is part of the DC
Adventure Comics adventure series. In issue #12 when the series was titled "New Adventure Comics", Joe Shuster and Jerry Siegel introduced the first version of the character Jor-L as a science fiction detective in the far future; the character would eventually become the alien father of Superman, although the first Superman story, in "Action Comics" #1, would not appear until more than a year after Jor-L's first appearance. The series' focus gradually shifted to superhero stories starting with the debut of the Sandman in issue #40. Other superheroes who appeared in the early days of "Adventure" included Hourman (from #48 to #83);