Theodore 'Ted' Grant was born in Gotham, long before there was a Batman keeping the streets safe. Back then a man had to know how to take care of himself, so to that end Henry Grant taught his son how to box. Young Ted took to the sport like a duck takes to water. In fact all his boxing training had the adverse effect of what his father had hoped for, that instead of keeping him out of trouble it was getting him into it. Ted had it in his mind that he had to prove he was the toughest kid on the block, eagerly jumping into any scrap he could find, regardless of the cause.
He eventually fell in with a gang of street toughs who called themselves the Wildcats. The group of late teen, young adult men dealt in petty crimes usually, while occasionally committing the odd stick-up job, all while having regular brawls with other youth gangs, hoping that they could catch the eyes of some of the cities Made Men, and make their way up to the big leagues of organised crime. While Ted didn't really care for becoming a full-time criminal, he did enjoy the respect he received for becoming one of Gotham's most effective bruisers.
Henry, worried about the direction his sons life was taking, figured he needed a more respectable outlet for his more violent urges, and so signed him up for an amateur boxing tournament. Ted demolished the competition, and in the doing he discovered what he wanted to do with the rest of his life. He wanted to be a boxer. However he wasn't keen to just abandon his old friends in the Wildcats, so while he wasn't in the ring he'd usually accompany them on whatever jobs they had lined up.
Things change though, and as the boxing demanded more and more of Ted's time he found he had less to give his gang. After all, this was a time when heavyweight boxing was dominated by some of the best names to ever grace the sport, men like Joe Fraiser, George Foreman, and of course Muhammed Ali after his forced exile. Ted couldn't afford to divide his attention. Things came to a head when he found out he had earned a chance at a title shot. He told the Wildcats he wanted out. The Wildcats, unsurprisingly perhaps, weren't best pleased. Ted was their muscle, their ace in the hole against the other gangs, and they didn't want to lose him. So they concocted a plan, one were they sent a crew round to Henry Grant's house, to beat Ted's father mercilessly and make it look like the work of one of the rival gangs. However Ted came home early that night, caught the men in the act, and reacted unsurprisingly, beating the crew in kind, even accidentally killing one man, John Travis.
Ted was defended under the Castle Doctrine, though he received a five year ban from boxing. Small punishment to his mind, for taking a man's life. He quit the Wildcats then, and became obsessed with making amends. At first he tried to pay back Travis' family, but they refused to speak to him at all, or accept any of his help, so he turned his efforts to charity. He tried his hand at anything he could find, church work, volunteering in soup kitchens, trying and failing to find something that might help him feel absolved of some of the guilt that was trying to crush him.
His salvation came one afternoon when he was loading boxes at the docks and a bunch of hood-rats arrived with the intention of squeezing some protection money from the dock-master. Ted was just thinking about intervening when none other than Green Lantern, member of the Justice Society, came floating down. The hero made short work of the villains, and left Ted with the knowledge of what he had to do.
He was to become a vigilante.
He would use his fighting skills to protect the little guys, to give back to society a little of what he had taken. With a makeshift costume costume and an Indian Scout motorcycle he took on the guise of the vigilante Wildcat. With his old ties to the underworld he knew just where to hit the criminals to make it hurt, and it wasn't long until he'd made some big waves. If boxing had been his career, then vigilantism had become Ted's passion.