The Blue Beetle began in 1939 as a comic book feature in Mystery Men. Following its debut it became a feature comic strip. and in 1940 made its way to the radio. Dan Garret is a cop who is frustrated by bureaucracy and turn to wearing special armor deigned by a friend. Garret becomes The Blue Beetle and criminal better beware!
A a radio program, The Blue Beetle did not last long -- just 48 episodes 13 minutes long. Here's an early 2-part episode from May 16, 1940. Frank Lovejoy took the tarring role early in the series only to be replaced by uncredited actors.
The Blue Beetle has had a longer life in comic book than on radio. First published by Fox Feature Syndicate, it ran for 60 issues. Charlton Comics then reprinted several of the adventures, but they had not bought the rights to the character, only some old plates. In 1964 Charlton revised the character, changing his last name to Garrett (two Ts) and significantly altering his backstory -- essentially making him a new character. The Blue Beetle showed up from Americomics and the DC, where he became Ted Kord, a former student of Dan Garrett. DC eventually passed the mantle on to Jaime Reyes, a Texas teenage. Jaime hooked up with the Teen Titans. Jamie's last appearance was in 2013, but in comic book world characters can be revived at a drop of the hat, so don't count The Blue Beetle out yet.
Enjoy Frank Lovejoy as The Blue Beetle.