It's interesting how cleanly 'The Big Three' American Comic Strips of the 1930s can be broken down, all of which informed the capes that followed:
a) Flash Gordon constructed the visual grammar of the Space Opera, it was the dreams of space-ships and wild alien worlds--of our Future in the stars.
b) Prince Valiant meanwhile was much more preoccupied with The Past. It was an excursion into our 'mythic' past, trying to visualize it and bring all our fantastical dreams to life as an epic.
If Raymond ventured forwards to stellar-empires, Foster went backwards to knights.
c) Terry and the Pirates on the other hand was much more rooted in 'the present' and instead of the past or future, its fascination was that of The Exotic Other.
It was about the Adventure in an Exotic Land, the same core of John Carter/Flash Gordon, but without the sci-fi sheen.
Without these three (and certainly a couple others, but especially these three), I don't know that you have superhero fare in the specific ways that you do.
Raymond, Caniff, and Foster are the backbone and visual, artistic foundations upon which so much has followed since.
This was an axiomatic piece of comic knowledge that every fan and pro took as a given at least up through the 1970's, at which point the new generation of fan-creators moved in, and looked back only one generation for influence rather than two.
The fact that kids these days do not know the work of Roy Crane, both an all-timer cartoonist AND a dipshit propagandist literally working with and for the US State Department, and how the creators of Superman were huge Crane fanboys (which shows!!) speaks to the tragedy of this even more.
