Superman is probably the most famous superhero of all time, and is getting crazier over the years. In the beginning (1938), he could jump really high, fly a little bit, is super strong, and has a “super” sense of justice.
Within the forty years between his first comic book and the first feature length Superman movie, he gained crazy abilities, such as being able to see through anything but lead, fly faster than planes, is weakened somehow by the rock that he was born on, and he can TURN BACK TIME BY SPINNING AROUND THE EARTH REALLYREALLYFASTSOMEHOW.
Now, he has an even wider array of superpowers like freezing breath, heat vision, laser vision, and infinite longevity. He is so super, he has died almost 10 times and either been revived or found out to not actually be dead. But in light of all of this, nothing is as superior as his greatest ability: to curl one of his hairs down, take off his glasses, and no one knows who it is. How. HOW.
He has captured the hearts of america, and is considered a cultural icon, representing the good ol’ red, white, and blue. Over the years, his popularity has grown, with success in ever aspect (comics, movies, television, action figures, fanfiction[icky], conventions, etc.). But the thing that has made his role in America so large is the involvement of the american people.
The collective storytelling through almost every possible medium has helped Superman and is image thrive and become an immortal symbol. It has transcended the barriers of a comic book character, to becoming a superhero, to becoming a staple, to an icon, to an eventual immortal. Superman himself may not be immortal, but Superman will live forever.