There's a general impression that the character we now call Shazam but was created as Captain Marvel was sort of a kinder, gentler version of Superman — particularly in the Golden Age. But I think that's not quite right, at least as far as the earliest issues of Whiz Comics are concerned. It might be more accurate to say that the character enabled the presentation of challenging themes through a child's eyes, and there was no theme more challenging or prevalent in comics in 1939 through the early 1940s than the world at war. A historically important series that became immensely popular during this period, there are a number of early issues of the Whiz Comics series up for auction at the 2021 August 15-16 Sunday & Monday Comic Books Select Auction #122133 coming up from Heritage Auctions.
It's an under-discussed aspect of Captain Marvel that a character with a military rank in his name — and a costume that was sort of a cross between a traditional superhero outfit and a military uniform in the earliest issues — was certainly meaningful during this period. Captain Marvel creator and writer William Lee Parker appears to have been a student of military history and perhaps even local New York area military history. After having been in the ROTC program at Princeton, he joined Squadron A — an exclusive volunteer troop cavalry and political club which began life as the New York Hussars. Parker seems to have been the formative voice in the creation of Fawcett's Captain Marvel, and while it's been suggested that he contributed specifics of the costume — such as the lightning bolt and the style of cape — a comparison of some specifics of the costume to various Hussar uniforms reveals a few more specific details. The cut and style of the cape does indeed appear to be inspired by styles that can be found in various Hussar uniforms, right down to the design at the cape's edges. The across-the-chest buttoning found in the original Captain Marvel design also appears based on military styles which can be found in Hussar and other styles of uniforms. Of course, even the notion of the Lieutenant Marvels plays into this military theme.
Early numbers of Whiz Comics include several examples of obvious war themes, and while the contents don't always match the interior Captain Marvel stories, several issues do feature Sivana and other villains attempting to take over America and/or the entire Earth via military campaigns or other means. A historically important series that became immensely popular during this period, there are a number of early issues of the Whiz Comics series up for auction at the 2021 August 15-16 Sunday & Monday Comic Books Select Auction #122133 coming up from Heritage Auctions.