"The highlight of Joe Shuster's visits to New York, the moment he really knew he'd arrived, was Superman Day at the second summer of the World's Fair, in 1940.  Duke Ducovny had arranged for Macy's to sponsor a big show featuring a parade and celebrity appearances—including one by Charles Atlas himself. 

"When Joe was a little boy, those bodybuilders in tights and trunks in the MacFadden magazines, Atlas chief among them, had given him his first glimpse of the superheroic.  In his teens Atlas's ads had first shown him a strongman as an enemy of bullies, and the very first published Superman story had included his visual joke on those ads.  Superman was a fantasy of Charles Atlas in more ways than one, and here was the World's Most Perfectly Developed Man himself, offering Joe his hand to shake."

An excerpt from Men of Tomorrow by Gerard Jones