"The Shadow" premiered on the CBS radio network on July 31, 1930 as
the narrator for a radio program called “Detective Story Hour” based on a
magazine of the same name.The radio drama series temporarily moved to 
NBC radio in October 1932. After returning to CBS it disappeared from the 
airwaves on March 27, 1935 and later began airing over the new Mutual
Broadcasting System as a half-hour series called “The Shadow” on
Sunday evenings and continued there until the final episode on
December 26, 1954.