Most comic-book aficionados agree that the Bronze Age of comics began in 1970, shortly after artist Jack Kirby left Marvel for DC Comics, which promised him a greater degree of artistic freedom since “Superman” editor Mort Weisinger had just retired. Among other things, the Bronze Age challenged established publishing conventions and brought the subject matter of comics into the modern day.

For example, in 1972, Luke Cage, the first African-American superhero, appeared. Around the same time, the concept of the superhero expanded to include foreign heroes (Banshee) as well as women heroes (Hawkwoman), who were more assertive and powerful than their predecessors. Unfortunately, many of the foreign and black characters simply reinforced racial and ethnic stereotypes, but some were genuine attempts to create a more diverse, inclusive world.

Similarly, Bronze Age comics began dealing with more real-world issues, beginning with “The Amazing Spider-Man” #96 and #97, which featured a very strong-anti-drug message at a t...ime when the Comics Code did not allow any references to drugs at all. Other comics followed suit: Green Lantern and Green Arrow teamed up to fight drug abuse and corruption. Captain America—now the product of a disillusioned, post-Watergate, post-Vietnam world—entered the realm of politics when he fought the Secret Empire, a conspiracy to take over America run by a villain who bore an uncanny resemblance to Richard Nixon.