The superhero comic-book had exploded following the introduction of Superman and the next few years similarly saw a plethora of these comic-book titles being adapted into their first film versions. Captain America joined a host of these that were made into serials. Others amongst these included Mandrake the Magician (1939), Adventures of Captain Marvel (1941), Batman (1943), The Phantom (1943), Superman (1948) and non-superhero comic-strip adaptations such as Flash Gordon (1936), Dick Tracy (1937), Buck Rogers (1939), Hop Harrigan (1946) and Brick Bradford (1947). Many of these also enjoyed sequels.
It involves a baffling double-take watching this serial and expecting familiar aspects of the Captain America story. The story everybody is conversant with is how weakling Steve Rogers was given an experimental formula by the US military that transformed him into a brawny super-soldier. Here there is no experimental formula and no suggestion that Captain America has anything other than ordinary powers. There is a Captain America costume and he does ride a motorcycle in a couple of episodes but is lacking his familiar shield. Moreover, Steve Rogers has been entirely written out and Captain America is now the alter ego of crusading district attorney Grant Gardner. Indeed, the serial fails to even give us an origin story for its hero. The modern aspect of the Captain America story where he was frozen in the Arctic and thawed out in the present-day did not come into Marvel continuity until nearly two decades later so at the point the serial was made he was no more than a patriotic superhero. However, while almost all of the Captain America comic-book adventures of the period featured the Captain on the battlefield fighting against Axis villains, here the Wartime setting, indeed any reference to the War, has been eliminated in favour of a standard crime-fighting plot. Essentially, the Captain America we have is no more than another version of Batman, someone with mundane powers who puts on a costume to fight crime. (It is speculated by historians of the serial that Republic had originally written the script as a sequel to one of their non-comic-book masked hero films or else that it was planned as an adaptation of another comic-book but that negotiations over the rights had fallen through and the script was simply reused). The main problem seems to be is that Grant Gardner is such a crusading District Attorney (whose activities go well beyond the usual field of being a prosecuting lawyer that a regular D.A. is supposed to be and into active investigation and hands-on apprehension of suspects), that there seems little difference between when he is operating as Gardner and when he puts on the costume and mask.
Serials are often tedious to watch today. At fifteen chapters of about fifteen minutes each, Captain America is four hours of drama where things are endlessly drawn out around either bad guys or the heroes trying to obtain/suppress a piece of evidence, vital artefacts or components and so on. There is little drama outside of these constant schemes. Everything is wound towards the cliffhanger that ends each episode with the hero or heroine in peril where audiences of the day would have to wait to the following week to find out how they get out of it. Among the mostly routine cliffhangers that turned up in serials, Captain America turns up some not bad ones Dick Purcell trapped inside a collapsing apartment building; one where he is downed in the path of a driverless oncoming tractor that we see crushing boxes, blocks and canisters as it heads towards him; a fight inside a burning crate; Purcell thrown down a mineshaft and an elevator cage dropped on top of him; Lorna Gray tied up underneath a guillotine.
One of the great bonuses of the film is Lionel Atwill, an actor who came to fame in various mad scientist films of the era including Doctor X (1932), The Mystery of the Wax Museum (1933), The Vampire Bat (1933) and with an especially memorable role as the wooden-armed police inspector in Son of Frankenstein (1939). Atwill has the time of his life and plays the villain as an aristocratic fop, outfitted with a monocle and at one point is even seen whipping an abducted man with a cat-of-nine-tails to get information.
Captain America was subsequently incarnated by Reb Brown in two laughably unconvincing tv movies Captain America (1979) and Captain America II (1979) that failed to go to pilot; was then remade on the big-screen with Albert Pyuns cheap Captain America (1990) starring Matt Salinger; and as the big-budget Captain America: The First Avenger (2011) starring Chris Evans, who subsequently played the role in the sequels Captain America: The Winter Soldier (2014) and Captain America: Civil War (2016) and the Marvel Comics team-ups The Avengers (2012) and Avengers: Age of Ultron (2015). The Captain America story is also told in the animated Ultimate Avengers (2006) and the Captain appears in other Marvel animated films such as Ultimate Avengers II (2006) and Next Avengers: Heroes of Tomorrow (2008).
Full serial online in several parts beginning here:-