Initially, Siegel was allowed to write Superman more or less as he saw fit,[REF] because nobody had anticipated the success and rapid expansion of the franchise [REF].
Schwartz retired from DC Comics in 1986, and was succeeded by Mike Carlin as editor on Superman comics His retirement coincided with DC Comics' decision to streamline the shared continuity called the DC Universe with the companywide-crossover storyline "Crisis on Infinite Earths".