As the industrial age dawned, literacy began to spread. As these new readers found themselves with more leisure time, they began to search for ways to entertain themselves. Daily or weekly periodicals began to become the norm, often including simple humorous and political cartoons. Poor Richard’s Almanac was among these.
The first instance of using multiple pages of cartoon panels of both text and images to portray a larger story is generally agreed to be The Adventures of Obadiah Oldbuck, in 1842. Since that point, comic books have been a growing art form.
The most common form of graphic novel produced in the US is the Superhero Comic, and is arguably the most popular. The popularity of the superhero comic began with the very first issue of Action Comics in 1938, which was also the debut of the hero known as Superman. This also spurred the event known as the Golden Age of Comics, which lasted throughout the 1940’s and resulted in millions of copies being sold of all kinds of comic books. This time of great prosperity would eventually end with the rise of television and the introduction of a self-regulatory force in the industry called the Comic Code Authority. The Comic Code Authority was brought about due to concerns that the comic book industry, and in particular the crime and horror genres, was corrupting the youth of America with themes of violence and depravity. The backlash from parents was so severe that Congress had three days of hearings to discuss the matter. While no legislation was passed, the Comic Book industry felt the need to create the Comic Code Authority as a means to protect itself. With these introductions, the adult themes of crime and horror comics disappeared. comics became associated with childish fare, and their popularity in the United States began to wane.
Across the globe in Japan, the Japanese form of graphic novel known as Manga was born and began its rise in popularity in Japan as their American counterparts declined. Across the ocean to the west, France and Germany were experiencing their own booms in the form of comics such as Tintin and Asterix the Gaul.
The 1980’s brought an end to the Silver Age of comics in America, usually marked by the release of the series’ Watchmen, V for Vendetta, and Maus. The release of these comics brought about a shift in the perception of comics, beginning to bring them back into favor with adult readers. The state of the comic book industry has been improving since the 1980’s, with the recent popularity of comic-book based movies being a large driving force to their increasing popularity. 
Types of Comic
To assist in our discussion of Graphic Novels, it is necessary to discuss the differences in the various kinds of Comics that exist, of which the Graphic Novel is just one form.
Graphic Albums are far more common in Europe than in the United states, and are typically large-print books of around 40-60 pages. They differ from comic books and graphic novels, in that they usually consist of several short stories rather than one conclusive narrative. 
A Graphic Novel is a comic that is the length of a novel, and tells a story from beginning to end. Limited Run Series that form a sufficient length story when taken as a whole are sometimes considered to be Graphic Novels. American Born Chinese, Fun Home: A Family Tragicomic, and Anya’s Ghostare examples of Graphic Novels. Watchmen, V for Vendetta, and Maus are examples of Limited Run Series considered as a whole to be Graphic Novels.
Limited Run (or Collected) Series
A Limited Run or Collected Series is a series of comic books that are intended to only have a few issues that tell a complete story from beginning to end through their run. Watchmen, Superman: Red Son, and V for Vendetta are examples of this kind of comic. 
“Manga” is the Japanese word for comic, but is used in America as the blanket term for japanese-style comics. Manga are often released in a lengthier format than American Comic Books, though less frequently and usually in black-and-white. Manga reads from top to bottom, but from right to left. One Piece, Dragon Ball, and Naruto are examples of Manga. 
The term “serial” is often used to specify an ongoing comic book series that is intended to run for a long period of time and feature many individual storylines. Batman, Spiderman, and other superhero comics often fall into this category.
Comics and Young Adults
Comics have been popular with young adults since the early days of their introduction. Unfortunately, not much emphasis has been placed on the study of the specific history that exists between comics and young adults. However, the associations between children’s fare and comic books has been ingrained into our perceptions enough to understand where the associations come from. Until the recent Hollywood focus on comic book heroes as a source of film ideas, the world of comics was considered to be the almost exclusive purview of children and teenagers. Those who were interested in comics as adults were often portrayed as being lazy, nerdy, childish, and elitist. One needs only look at the Simpsons character “Comic Book Guy,” who is referred to by that tile rather than his actual name, Jeff Albertson. Adults with interests in comic books are often depicted in a similar fashion, even to this day. Perhaps it is this association with childhood and adolescence born from the age of the Comic Code Authority that causes us to associate comic books with young adult literature, even though comics specifically targeted towards young adults seem to be in the minority.
Often, when people refer to young adult literature, comics are lumped in with the rest of the mix. With the dissolution of the Comic Code Authority in 2011, comic books publishers now rely on their own internal rating systems. Of course, as with all dramas, the borders between what is recommended for adults and what is recommended for young adults is often blurry. For instance, the Marvel Rating System is rather vague in its description of what makes a comic fall in one category or another. This can lead to comics that test the acceptable limits already in place. This, combined with the recent movement of young adult literature towards representing the darker sides of the teen experience, only serves to further blur the lines.