During the Great Depression/World War II era, Comic Book Heroes began spawning from all sorts of different writers, To enlighten and entertain the imaginations of both Children and Adults. Action Comics #1 is considered by some to be the first superhero comic, Making Superman the one of the world's first comic book superheros to be created. Even though there had been comic books before the 1900's, these were called comic strips (comics that were written and drawn by an artist or cartoonist and published in newspapers). DC was one of the first comic book publishing companies to do entirely original stories, rather than reprinting comic strips. Because of Superman's popularity during that period, superhero comic books slowly began to dominate that era in comic book history.
During the late 1930s and the early 1940s, DC, Timely (early Marvel) and All American Comics created the heroes that would later become iconic characters in comic book history. Characters such as Batman, Captain America, Wonder Woman, Namor the Submariner, Jim Hammond/Human Torch, Alan Scott/Green Lantern, Flash, Hawkman, Aquaman were created as well as many more.
Sales records were curated even from the beginning of the Golden Age of Comics, Captain Marvel which at the time belonged to Fawcett Publications had sales of over 1.4 million copies per issue published under the title Whiz Comics. Timely sold over 1 million issues titles which contained iconic names like Captain America, Namor the Submariner and The Human Torch (Jim Hammond). It is unknown how long this Golden Age of Comics lasted, but some say that it started in the late 30s and ended in the late 40s, while others think that the Golden Age of Comics ended in the early 50s. This era in comics was followed by the the Atomic Age (often depicted as the periods between 1950 and 1955). This was named as such as some characters had developed their powers as a result of the nuclear age. The Silver Age of Comics followed.
"DC Comics" released the First Issue of World's Finest Comics during this period which featured Batman, Robin, and Superman on the Cover. This established that DC super-Heroes lived in the same universe, and the first version of what is now known as the DC universe was born. Other crossovers were created, such as The Justice Society of America, the world's first comic book team.
The golden age is known for some plot devices that don't often appear in modern comics. Two of the most common were realistic androids and the need by heroes to convince someone in their closest circles (or the public at large) that their heroic persona and their alter ego were in fact different people.
Many Golden Age characters lost their copyright status and became Public Domain. It is because of this that the characters have been written about by many different comic Companies. America's Best Comics has done a lot with the Public Domain, Golden Age characters. Dynamite Entertainment has as well.
In Dynamite Entertainment all the Golden Age heroes were trapped by the Urn of Pandora. There they sat in limbo for sixty years before they were released. Being in limbo gave some of the heroes new powers and psychological traumas.