In 1934, Orson Welles came to Broadway in a production of "Romeo and Juliet" and within a year he was putting his mellifluous voice to use by doing a lot of radio work, including as part of the stock company, imitating famous newsmakers, on "The March of Time." While producing and directing shows on Broadway, he was also making a name for himself as the title character on "The Shadow" and, later, scaring America to death with "War of the Worlds." Today we consider Welles's work as a rising star on the radio, leading to an offer from Hollywood.
Sources:
Broadcast Hysteria: Orson Welles's War of the Worlds and the Art of Fake News, by A. Brad Schwartz
Orson Welles on the Air: Packaging Welles, orsonwelles.indiana.edu
"This Ageless Soul," Russell Maloney, The New Yorker, October 1, 1938
Rosebud: The Story of Orson Welles, by David Thomson
The Mercury Theatre on the Air, mercurytheatre.info