Today’s Wonder of the Day was inspired by Dane. Dane Wonders, “Who invented Comic strip art?” Thanks for WONDERing with us, Dane!

What's that way up there in the sky? Is it a bird? Could it be a plane? If you're a fan of superheroes, then you've probably already guessed who it is. It's Superman!

Superheroes are everywhere these days. If you go to the movie theater, it seems like there's always a new superhero movie playing. From Batman and Captain America to Iron Man and Green Lantern, there's no shortage of fascinating films to feed our hunger for heroes.

Although it seems like superhero movies are especially popular recently, they've actually been a fan favorite for a long, long time. Superheroes didn't debut in movies, though. They actually got their start in the pages of the earliest comic books.

So who exactly invented comic books and when did they first appear? Scholars believe the oldest comic book in the world is The Adventures of Obadiah Oldbuck, which was published in Europe in 1837.

Although it looked more like a picture book than what most Americans would consider to be a comic book, its author, Switzerland's Rudolphe Töpffer, is widely considered to be the creator of the picture story, comic strip, and graphic novel/comic book.

The first American comic book, Funnies on Parade, was published in 1933. Rather than original content, however, it was composed of reprinted comic strips from newspapers, including such favorites as Mutt and Jeff, Joe Palooka, and Skippy.

It was very popular and led to the publication of other syndicated comic strips from newspapers. It wasn't long, though, before demand for comic books led aspiring cartoonists, suffering from high unemployment as a result of the Great Depression, to create inexpensive original content.

It didn't take long for the fledgling comic book industry to take flight. In fact, the golden age of comic books began with the 1938 debut of Jerry Siegel and Joe Shuster's Superman character in Action Comics #1.

Still the most recognizable comic book character of all time, Superman made comic books very popular and inspired the creation of a wide variety of characters with all sorts of superpowers. Soon comic book fans could buy comic books featuring Captain America, Batman, Green Lantern, Wonder Woman, Flash, Plastic Man, Captain Marvel, and many others.

Comic book sales increased dramatically during World War II. People could not get enough of the patriotic, inspirational stories of good overcoming evil. Plus, they were cheap. Captain America was particular popular during the war.

Comic books remain popular today. Classic comic books can also be extremely valuable. Action Comics #1, in which Superman made his debut, is still considered the most valuable comic book in the world. In 2014, a copy of the classic comic sold for over $3 million!

Wonder What's Next?

Tomorrow’s Wonder of the Day is really taking shape…especially if your name is Gumby!