Friday is National Comic Book Day

(CNN, KYMA) - Friday makes National Comic Book Day, a day to go back to the roots of superheroes and villains.

Comic books are a true American original. They started as literal books of reprinted humorous comic strips.

The first known hardcover comic book was printed in 1842. They didn't evolve into what we know today until almost 100 years later.

From there, they took off into serialized stories starring a variety of colorful characters.

Comic books evolved to feature all sorts of stories, themes and art styles. They've also gone on to become huge drivers of Hollywood films.

Movies featuring "The Avengers" and "Spider-Man" have been some of the most successful of all time, raking in billions at the box office.