The original Golden Age Blue Beetle was Dan Garret, the son of a police officer who was killed in the line of duty by a criminal. The Fox Feature Syndicate version of the character debuted in Mystery Men Comics #1 (Aug. 1939), with art by Charles Nicholas Wojtkowski (as Charles Nicholas) and began appearing in his own 60-issue series shortly thereafter; however, Holyoke also released some issues of the series during it’s slightly sporadic existence.
Rookie patrolman Garret donned a bulletproof costume (described as being made of a chain-mail which was "as thin and light as silk"), and temporarily gained superhuman strength from ingesting the mysterious vitamin 2-X.
The supporting cast remained fairly stable throughout this original run, and included Joan Mason, a crime reporter for the Daily Blade who would eventually star in her own backup series, and Mike Mannigan, Dan's Irish-stereotype partner on the police force. Dr. Franz, a local pharmacist (and inventor of the bulletproof suit and 2-X formula) played a prominent role in the first few issues of the run, but he was soon phased out.
A popular character of the Golden Age era, the Beetle also had a short-lived newspaper strip (drawn by the legendary Jack Kirby under a pseudonym), and a radio serial that ran for 48 thirteen-minute episodes. When super-heroes fell out of vogue in the late 1940s, Fox downplayed the Beetle's super-heroic angle (his superpowers were removed) and eventually relegated him to a hosting true crime stories within his own series before the book was cancelled.
The featured artwork is from DC Comics Secret Origins #2 (May 1986) by Gil Kane.