A comic book is a type of magazine or novel that tells a serialized story through comic strips, typically focusing on the adventures of superheroes. Originally introduced as a collection of reprinted newspaper strips in the early 19th century, comic books grew to feature wholly original stories in the 1930s. The medium became especially associated with superheroes after the release of Action Comics #1 in 1938, which was the first appearance of Superman.
As of 2021, comic books remain a popular entertainment medium, thanks to numerous successful movie adaptations of Marvel and DC Comics superheroes. According to Publisher's Weekly, sales of comic books and graphic novels topped $1.28 billion in 2020, an all-time high.
The first-ever comic book is widely considered to be The Yellow Kid In McFadden's Flats, published in 1897, due to it actually contained the phrase "comic book" on its back cover. The publication did not resemble the modern interpretation of a comic book, and was instead a black-and-white book that featured reprints of popular newspaper comic strips. Comic books retained this format until 1935, when National Allied Publications (a precursor to DC Comics) published New Fun #1, the company's first comic book and the first to feature wholly original material.
The 1938 release of Action Comics #1, which featured the debut of the superhero Superman, ushered in the Golden Age of comic books. Defined as the period between 1938 to 1956, the Golden Age saw comic books attain a level of popularity that would not be seen again until the 2000s. In addition to Superman, many other famous comic book characters and superheroes were created during this era, including Batman, Wonder Woman, Captain America, the Human Torch, The Flash, and the Green Lantern. Non-superhero comics became popular during this time period as well, such as the Archie Comics, which made their debut shortly after Superman in 1941.
Comic books went through a variety of trends in the following decades. During the Silver Age of Comic Books, from 1956 to 1970, comic book publishers established a Comics Code Authority in response to parent backlash and criticism about certain stories. This comics code significantly affected what kinds of stories comic books could tell, as it required that "good always triumph over evil" and forbid depictions of "vampires and vampirism, ghouls, cannibalism, and werewolfism." Many horror, crime, and romance comics were subsequently canceled, leading many Silver Age comic publishers to instead develop stories using Golden Age superheroes. Comics from this decade were known for their campiness and silly plot lines.
In 1971, the Comics Code Authority relaxed some of its strict standards. This move is widely considered to be the start of the Bronze Age, which lasted until 1985. The Bronze Age signaled the return of some horror comics, as well as the appearance of some darker storylines in superhero stories, such as the murder of Spider-Man's girlfriend at the hands of the Green Goblin or Iron Man's struggle with alcoholism. The Bronze Age also saw DC and Marvel, which had realized most of their characters were caucasian men, create some more diverse superheroes, such as Storm, Black Lightening, Blade, and the Green Lantern John Stewart.
The Dark Age of comics, from 1985 to 1996, was kicked off by DC Comic's release of Crisis on Infinite Earths, a limited series that was a massive success for the company. Stories featuring anti-heroes were especially popular during this era, such as Alan Moore's graphic novel Watchmen. The end of the Dark Age also saw a massive sales slump and industry downsizing due to low popularity. The sales slump contributed to the bankruptcy of Marvel Comics in 1996.
The Modern Age of comic books, from 1996 to present, has seen comic books attain a renewed sense of relevance and popularity. The success of movie adaptations, especially the Marvel Cinematic Universe, has greatly contributed to this renewed popularity.
The comic book industry has enjoyed renewed relevancy and successful sales in recent years. In 2020, comic book sales surpassed $1.28 billion, representing a 6 percent increase over 2019 levels, according to Publisher's Weekly. Most comic book and graphic novel sales came from bookstores, followed by independent comic shops and digital downloads.
Twenty first century comic book popularity has not been exclusive to literature. Many successful movie and TV show adaptations have been made from comic book characters and stories. The most successful of these has been the Marvel Cinematic Universe, which as of 2021 is the highest-grossing film franchise of all time with over $23 billion in worldwide box office revenue. Other successful adaptations include the CW's Riverdale, a TV series featuring characters from the Archie Comic's universe, as well as Christopher Nolan's Batman trilogy of films.