Rex Tyler operated as the "mystery man" called Hourman during World War II as a member of the Justice Society of America. After the war had ended, Tyler continued to fight crime, though he was noticing that the Miraclo pills that were giving him his "hour of power" abilities were losing their potency too soon. Over the course of the late 1940s, Tyler was experimenting with adapting the Miraclo formula in the hopes that it would continue to give him his abilities for one hour, only to experience various hallucinatory side effects (which he flatly denies) and the growing fear that he was becoming a drug addict. Eventually, one of his experiments ended up stabilizing the "hour of power" effect that it originally had on him.
Around early 1950, Tyler was contacted by Johnny Chambers (Johnny Quick) and various fellow superheroes who discovered from Tex Thompson's diary that he was really the Ultra-Humanite and that Dynaman was really Adolf Hitler's brain transplanted into Daniel Dunbar's body prior to the transformation. Later that year, at a rally in Washington, D.C. where all costumed superheroes were to appear by Presidential decree to show their loyalty, Tyler showed up under the pretense that he would be joining Thompson's campaign and donating his Miraclo formula to the American public, but was really going to use that opportunity to expose Thompson and Dunbar. However, before he could do that, Joan Dale (Miss America) bravely made the attempt to expose them herself when the Ultra-Humanite had Robert Crane (Robotman) silence her by murdering her in public. Tyler took over for Dale in the exposure of both Thompson and Dunbar, causing Dynaman to show his true colors and to attack the various superheroes present. Tyler then helped a confused Al Pratt (Atom) see the truth behind Thompson's deception long enough to give his fellow Justice Society member a hand in fighting Dynaman.
Years later, after Thompson and Dynaman were killed, Tyler continued to fight crime as Hourman, also fighting the addictions that were haunting him.
About ten times the strength of a man his age who engages in regular intensive exercise when using Miraclo.
Various hallucinogenic side effects that came with his experimenting with the Miraclo formula.
Miraclo pills, which give him the strength of ten men for about an hour, as they were originally designed to do.
- This version of the character is native to the JSA: The Golden Age series of stories.
- 4 Appearances of Rex Tyler (JSA: The Golden Age)
- 2 Images featuring Rex Tyler (JSA: The Golden Age)
- Quotations by or about Rex Tyler (JSA: The Golden Age)
- Character Gallery: Rex Tyler (JSA: The Golden Age)