Tex Thompson operated as the "mystery man" known as Mr. America and then later Americommando during World War II. Around the later years of the war, Thompson went undercover behind enemy lines in Europe along with his friend and fellow crimefighter Paul Kirk (Manhunter) in order to take down the Nazi super-agents including Otto Frentz (Parsifal). Thompson was eventually captured, and his brain was removed and replaced by the Ultra-Humanite's, who then returned to America after the war under the guise of Thompson, being credited for the killing of Adolf Hitler when in fact the Ultra-Humanite had Hitler's brain removed and then later transplanted into the body of Daniel Dunbar to become his super-agent called Dynaman.
- This version of the character is native to the JSA: The Golden Age series of stories.
- 4 Appearances of Harold Thompson (JSA: The Golden Age)
- 2 Images featuring Harold Thompson (JSA: The Golden Age)
- Quotations by or about Harold Thompson (JSA: The Golden Age)
- Character Gallery: Harold Thompson (JSA: The Golden Age)