The Golden Age of SF is universally dated from the July 1939, issue of Astounding because that's when "Black Destroyer," A. E. van Vogt's first SF story, appeared. Isaac Asimov's first story also appeared in the same month but nobody—as Asimov himself admits—noticed it. People noticed "Black Destroyer," though, and they continued to notice the many other stories that van Vogt wrote over the fol...