I just bought a VHS of the old Captain America adventure serial for $1.00 at a garage sale. I watched the first episode last night. I had seen several episodes as a child when our local PBS affiliate would air old adventure serials on Saturday nights. I didn't remember much about it though.
Captain America was created by Joe Simon and Jack Kirby for Timely (now Marvel) comics in 1940. Weakling Steve Rogers volunteers for an experimental super serum which transforms him into the powerful and muscular Captain America. He spends the war fighting Nazis. The first issue of Captain America Comics, while dated 1941, was actually published one year before America entered World War II. Cap was retired by Marvel when super heroes went out of vogue, but he was revived in the 60s when Rogers, who had been in suspended animation, was thawed out.
The serial was the first time a Marvel/Timely superhero had appeared in any medium outside the comics. It is good for nostalgia and maybe one of the best serials of its era. But it is glaringly inconsistent with the comic version. Absent from the movie is Cap's trademark shield. Instead he carries a gun, which seems very odd. The origin story and alter ego is also changed. Cap is a district attorney named Grant Gardner in the serial. While the serial was released during the war (1944) Cap strangely enough doesn't fight any Nazis.
Of course the forthcoming Captain America: The First Avenger will be more true to the comic origin. Other live action versions have included two 1979 and 1980 TV movies starring Reb Brown. The 1990 movie was the most faithful to the comics in many respects, but was panned by critics. I still haven't got around to that one, but I am looking forward to the latest movie incarnation of Captain America.