Superman the offer. Siegel and Shuster submitted their work in late February and were paid $130 (AFI $) for those 13 pages. In early March they signed a contract (at Liebowitz's request) in which they released the copyright for Superman to Detective Comics, Inc. This was normal practice in the business, and Siegel and Shuster had given away the copyrights to their previous works as well. Superman was finally published on April 18, 1938, in the first issue of "Action Comics". The magazine sold very well, and feedback from readers showed it was because of Superman. Siegel and Shuster read pulp
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);