As the war progressed it was almost as if every Tom, Dick and Harry was getting superpowers to help with the war effort. The Flash was being doused with chemicals during a thunderstorm and discovered he was the fastest man alive, a biochemist stumbles across a vitamin that makes him the strongest man alive for an hour at a time and becomes known as Hourman, The Green Lantern finds a lantern that when crafted into a ring gives him superhuman powers, which is all very well and good but what about someone who could never hope in a million years to be as big and strong as these heroes and yet wanted to do his bit in the war? Enter Billy Batson.
Billy really has had it tough. Homeless, through no fault of his own, he's a newsboy whose interest in a mysterious stranger leads him to a secret subway tunnel, inside of which is a subway car with no visible driver takes them to an underground tunnel with seven statues depicting the Seven Deadly Enemies of Man (Pride, Envy, Greed, Hatred, Selfishness, Laziness and Injustice). And who is this mysterious stranger? A wizard by the name of Shazam. Now, this wizard was an exceptionally old wizard (having been born in Ancient Egypt) and, well, to be honest he's fed up with humanity that is until Billy comes along. He can't put his finger on it, but he believes that Billy has the best of human nature in him and so he gives him the abiltly to become a man who has the wisdom of the king of Israel Solomon, the strength of the Greek god Hercules, the stamina of Atlas forced to separate the sky from the ground, the power of Zeus the king of the Greek gods, the courage of Achilles the Greek military leader and the speed of Mercury, the messenger of the Greek gods. As you can imagine Billy is rather taken away by all this and doesn't want them at first, but when the wizard tricks him into saying his name, he becomes transformed into Captain Marvel. However, his first transformation comes at the cost of the wizard's life as a stone balanced above his seat crashes down and crushes the wizard to death, but his ghost advises the Captain that whenever a brazier, a type of barbeque used in ancient times, is lit he will pass on vital information.
Well, this certainly puts a new spin on things and before Billy knows where he is, he becomes a news reporter for a local radio station (very handy for finding out about things that shouldn't be going on) and soon gets involved with the likes of Superman (which whom he has a very friendly relationship with)

"Great heavens, what is there to adulate in me? Am I particularly intelligent, or remarkably studious, or excruciatingly witty, or unusually accomplished, or exceptionally virtuous?"
(The Duke of Dunstable, Patience by Gilbert and Sullivan)