Among 100 years of civil unrest, global conflicts and technological advancements, Americans have clutched their comic books.

But why do they connect with the exploits of an alien, a patriot, a spider, a bat and a teenager?

Superheroes function as entertainment — people can escape into the struggles of the superhero.

"It's the idea of trying to live vicariously a life you can't live, but at the same time probably to feel better about your own life and existence, because the world is a very scary place," said Tyler Jones, an Arizona Student University graduate student who wrote his honors thesis about superheroes and comic books.

Much of the conflict in comic books involves the current societal issues of an era, such as WWII or the rise of the Internet. Just as normal citizens must confront the challenges of their era, superheroes must struggle with the same culture and mindset. The definition of a superhero goes beyond a bright costume and powers — it channels into culture's lust for a zeitgeist, the spirit of the times.

"Superhero comics offer a surprisingly valuable window into twentieth century U.S. history," said Katherine G. Aiken, the dean of the College of Letters, Arts & Social Sciences at the University of Idaho in an article, "Superhero History: Using Comic Books to Teach U.S. History."

Each portion of American history can be represented by a hero as a summary of the opinions and emotions of that period. Spider-Man's youthful doubts of the '60s do not associate with Captain America's blatant patriotism of the '40s and '50s.
Superman: A beacon of justice (1938-1940)
The product of two shy, bespectacled high-school students, Superman found his way into thousands of young imaginations with the first issue of Action Comics in 1938. Jerry Siegel and Joe Schuster described their creation, America's first superhero, as "Champion of the oppressed, the physical marvel who had sworn to devote his existence to helping those in need!" These words described Superman's appeal to Americans coping with the end of the Great Depression and the beginning of the New Deal.

Superman easily overcomes classic 1930s government pitfalls: the denial of entrance, information and justice.

Never before had the public witnessed such an invincible force for justice. Jenette Kahn, a former president of DC Comics, describes Superman in A Complete History of American Comic Books as, "A fictional character who lives so vividly in our imaginations that we suspend our incredulity and believe for the reading and rereading of the comic."
Captain America: Mr. Patriotic (1941-1955)
Captain America's comic book origin begins with a villain. While conflicts in the old "Superman" comics stuck to issues of corruption in America, Captain America's antagonists moved outward to the enemies of the United States and the United Kingdom during World War II. Co-creator Joe Simon recalls the origin of Captain America in his biography, My Life in Comics:

"I thought to myself, Let's get a real live villain. Adolf Hitler would be the perfect foil for our next new character, what with his hair and that stupid-looking moustache and his goose-stepping" p.87

And so arrived Captain America, donned in red, white and blue. The famous first cover with Captain America slugging Hitler in the face hit newsstands (where comics were typically sold) about a year before the U.S. officially announced its involvement World War II, according to Bradford Wright in Comic Book Nation.

This comic did everything to support the government and unify Americans. In an interview, Simon said, "He wasn't just meant to be a propaganda device. He was designed to be one of us, and to represent all of us as the best America has to offer."

Simon and Kirby wanted to boost American patriotism and input their support for the country they loved. They involved children in the war effort when Captain America recruited a young sidekick named Bucky to help him fight the "vicious elements who seek to overthrow the U.S. government!"

Captain America represented the World War II era and readers, young and old, understood the nature of his struggles, the need to unify and defeat the enemy.
Spider-Man: youthful doubts (1960-1975)
Before "The Amazing Spider-Man," readers only idolized their heroes. Though Superman and Captain America lived through timely situations like the New Deal and World War II, they "were always in control, rarely impulsive, and never irrational," Wright said. But American values were changing, especially as baby boomers reached their adolescent years. An era of teenage rebellion arose, along with confusion and questions of identity.

Stan Lee and Steve Ditko of Marvel Comics co-created a new hero, a teenager who only years ago would have been a sidekick. Lee explained in an interview with National Public Radio:

But I thought it might be interesting to make the teenager the actual hero. What would happen if a teenage kid got a power? And then I thought it'd be even more interesting to make him a kid with the normal problems that so many teenagers have.

Spider-Man constantly questions his purpose as a hero. His life, minus the radioactive spider bite, could be any teenager's life.

The August 1962 edition of Amazing Fantasy, featuring "The Amazing Spider-Man" became Marvel's best-selling book in months, Lee said in A Complete History of American Comic Books. Spider-Man quickly earned his own comic and thus became, as Lee wrote at the end of his first adventure, "America's most different new teen-age idol."

When he first receives his powers, he performs on television for personal monetary gain, overjoyed with independence and self-esteem. As he, "breathes the first sweet scent of fame and success," he does not care to stop a burglar who speeds in front of him. When a police officer questions his apathy, Parker responds, "Sorry pal! That's your job! I'm thru being pushed around, by anyone! From now on I just look out for number one — that means me!"

Here, Spider-Man/Peter Parker is a real person under a costume. He does not have assumed morals and ethics. Like any human being, he learns his personal code over time. Just as young Americans were captivated by Superman's and Captain America's exploits in history, they were captivated by Spider-Man's historic challenges in identity.
Batman: The dark deviant (1980-1999)
Superman, Captain America and Spider-Man all resonated most with readers in the eras from which they originated. Batman was different.

Though Bob Kane created the first Batman comic just one year after Superman's debut, Batman has since evolved through many periods and personas. Batman was a political reformer in the '40s to Adam West's campy '60s TV show to a moderate voice between political rivals in the '70s.

But the Batman of the '80s through the '90s marked a trend in comic books that redefined the superhero. Comic books and their characters (or at least some) grew up. "Superheroes traditionally had stood as the champions of a good citizenry menaced by aberrant wrongdoers. In this cynical era, however, it was the superhero who was the aberration," Wright said.

By this period, comic books were as middle-aged as the Bruce Wayne in The Dark Knight Returns. So were many of the readers. This older, more skeptical Batman sold well because he breathed life into comics that before were dominated by corny dialogue and sappy plotlines written for adolescents.

"The audience was changing, therefore, not only in terms of average age, but also in terms of general cultural sophistication," said Patrick Parsons in Batman and his Audience, a chapter in The Many Lives of Batman.

People liked the new dark, edgy Batman. Frank Miller explained in an interview in The Many Lives of Batman, "What better image for a time of despair? We live in very dark times. It fits that this would be our hero."
Kick-Ass: The modern superhero, 2000-2012
"Kick-Ass" incorporates the superhero as a mixture of self- doubt, 21st century technology and pop culture references. These elements allow the reader to identify with protagonist Dave Lizewski.

Lizewski is the modern teenager, with a cell phone, computer and a MySpace (the first comic was published at the end of 2009).

But he also possesses the elements of the classic superhero: a costume, an origin story, insecurities and an urge to help the helpless.

Lizewski earns his title as a superhero through YouTube fame. Someone films him on the their cell phone as he defends an innocent man against a gang of three. Instead of "roaming the streets" for crime, Kick-Ass roams his MySpace messages for crime-fighting requests.

While people looked to Superman as the savior of the oppressed in the late '30s, today the hero rarely solves society's problems.

"I wasn't the class clown or class genius or class anything, really. Like most people my age, I merely existed," Lizewski said.