Eighty-five years ago today, the October 15, 1939, issue of Broadcasting magazine carried this ad for the Green Hornet. The radio program had originated three years earlier on Detroit station WXYZ, and was carried on various networks over the years. This ad indicates that it was in syndication in 1939, with its roots still in Detroit. The ad promised a movie to be released soon, and it was indeed serialized in the 1940s.
The Green Hornet was actually the great nephew of the Lone Ranger, who also got his start on WXYZ.
One of my radio favorites, along with TLR, Sgt. Preston.