Although comic books today are a dying breed of literature (Marvel has, after 50+ years, canceled The Fantastic Four, once billed as "The World's Greatest Comic"), they were in their heyday during the 1940's and 1950's (as was the Lone Ranger), when something called the Kefauver Hearings occurred in 1954, causing the then-in-vogue horror comics to die out by 1955 due to implementation of the Comics Code Authority, without which approval comics could not be distributed and sold via normal channels. The comic cover pictured was the final straw (unbelievably, it was edited from a far gorier version) and was the beginning of the end for EC Publications, of which the sole survivor would in 1955 become MAD Magazine (magazines were not subject to the Comics Code as were "comic books).
Dr. Fredric Wertham’s 1954 book, Seduction of the Innocent, was an American bestseller – it tapped into the fears of parents from sea to shining sea - that first led to the Kefauver Hearings and then to a frenzy of censorship in the comic book world. The irony, however, is that the book was so poorly researched, that much of its content was simply made up or misrepresented (it was Wertham's opinion that Batman and Robin were in an obvious homosexual relationship). Of course, the public didn’t give a hoot about facts, and Seduction of the Innocent became a sensation due to its many lurid illustrations, examples of which, with running commentary, can be found here.
Stan Lee, who recently died, was head of Atlas Comics during this period, and he too published horror titles and others that ran afoul of the new code. Consequently, he left Atlas and went on to found Marvel Comics in the early 1960's, and the rest, as they say, is history.
If you'd like to see more of what you have most probably missed-out on, but which most probably corrupted your grandparents, you may do so by visiting here. (It should surprise no one that I own the complete EC library.)