Mr. Keen, Tracer of Lost Persons ran from October 12, 1937 until September 26, 1955, making it one of radio's longest running shows. It first appeared on the NBC Blue network and switched to CBS radio in 1942, where it remained until the end. Of almost 1700 episodes only 59 are said to survive, although 618 scripts are known to exist.*
Robert W. Chambers' 1906 fix-up novel The Tracer of Lost Persons is generally considered the source for this popular radio series. That book, Mr. Keen was primarily interested in romantic themes rather than the murder, mystery, and mayhem involved in the radio show. Frank and Ann H
Hummert updated and brought the character to radio. Over the airwaves, Mr. Keen was never referred to by his first name; although sometimes he was called "Boss" or (more rarely) "Peachy." Writer Jim Cox, in his 2004 book on the radio show, revealed that Keen had the unlikely first name of Westrel. Is there any wonder Keen hid that name?
Bennett Kilpack played the title character for most of the show's run, followed by Philip Clarke and Arthur Hughes. Jim Kelly played Mike Clancy, Keen's stereotypical Irish "Watson." Mr. Keen, Tracer of Lost Persons could never be considered great art. But is was great fun.
Ivan Shreve has an interesting perspective on the show here:
Click on the link below to hear the episode from February 24, 1944, "The Case of Murder in the Air."
* Dates and number of episodes vary. I've tried to use those I felt were most likely. So feel free to take these details with a grain of salt.