How Captain Marvel Became the Mighty Thor

Captain Marvel had vanished almost a decade before, and to the young comic book readers of 1962 that might as well have been forever. So Stan Lee and Jack Kirby decided it was time to revive the popular concept, with interesting variations. Here's a caped, flying, super-strong hero with the powers of the gods, transformed from his ordinary existence by a bolt of magical lightning when danger threatens. Even disability, as a metaphor for weakness, was carried over from Fawcett to Marvel. Both Freddy Freeman, the alter ego of Captain Marvel Jr., and Dr. Don Blake, Thor's secret identity, were lame.

 Whiz Comics #2 (February 1940), published by Fawcett Comics.