Superman is really the all-father of superheroes. He is the Odin from which all else springs forward. Without Superman, there's no Marvel or DC, no billion-dollar blockbusters. His logo is one of the three most recognizable symbols on the planet, and it stands shoulder to shoulder with the crucifix and the Jewish star. Superman became a worldwide phenomenon and was created by two working-class kids from Cleveland, Jerry Siegel and Joe Shuster.
Superman is for justice and it's kind of ironic that there was a great injustice done to his creators. Siegel and Shuster lost everything, and just like Superman, they demanded justice. They fought for years to receive proper credit and compensation.