Astro City is a anthology series centered on a fictional American city of that name. Written by Kurt Busiek, it explores how ordinary people and the superheroes and villains themselves react to living in their world. Many of the heroes are direct homages to Marvel/DC superheroes like Samaritan (Superman) or The Confessor (Batman) but different enough to hold up against them.
The Dark Age storyline story starts at the late 60s-early 70s and ends in the mid-80s, when some super-heroes were declining in popularity, due to general mistrust of authority figures, along with the more violent, gritty tactics that some super-heroes were practicing. The storyline mirrors what was happening in comics during the Bronze Age of comics.