After the beginnings of the annual get-together betwen the JLA and JSA, a silent alarm is triggered inside Sandman's old lab.
The Justice League of America, teams up with the Justice Society of America, to take down the Horned Owl Gang. Afterwards, the Sandman races off, responding to an alarm emanating from his car. The Justice League of America, and he Justice Society of America, follow the Sandman back to his residence. There, they find the Sandman standing in his hidden lair. The room is in ruins. The Sandman reveals a dark secret. Years ago, he had been working on a new weapon, the silicoid gun, for use in the fight against crime. Test firing the weapon caused an explosion, the brunt of which caught the Sandman's teen sidekick, Sandy, the Golden Boy.
Sandy was transformed into a giant silicon monster, with intentions of taking over the world. Almost immediately, however, the creature collapsed. The Sandman placed Sandy in a gas filled glass chamber, to keep him sedated, until a cure for his condition could be found. The chamber has been destroyed, and Sandy is gone. The Justice League of America, and the Justice Society of America, split into three teams to search for Sandy. The Elongated Man, the Hourman, and Superman confront Sandy at an outdoor wedding. Sandy quickly subdues the three heroes. The wedding party hurl pies at Sandy, distracting the creature long enough for the three heroes to recover.
The Elongated Man, the Hourman, and Superman forcibly restrain Sandy, only to have the creature transform into sand, then melt into the ground. A search of the surrounding environment turns up nothing. Sandy reappears on a baseball field, where he is confronted by the Batman, the Flash, and Wonder Woman. Wonder Woman lassoes Sandy, but her magic lariat passes right through him, when she tries to pull it taut. The Batman is struck down. The Flash races around Sandy, trapping the creature in a super-speed generated vortex. Sandy again transforms into sand. The powerful winds carry Sandy's granulated form across the field, creating a localized sandstorm.
The Batman screams at the Flash to stop, as the sandstorm threatens to overwhelm them. Sandy next reforms on a beach. A group of men attack Sandy, but the creature easily repels them. The Green Lantern and the Sandman confront Sandy. The Green Lantern's power ring energy is completely ineffective against Sandy, due to the golden color of his silicate body. Sandy absorbs the power of the ring, and feeds it back to the Green Lantern, knocking him unconscious. The Sandman douses Sandy with the same tranquilizing gas that incapacitated the creature for decades. The breeze coming off the ocean, however, dissipates the gas.
Sandy lumbers towards the Sandman, who ceases all hostilities, believing that his former sidekick could never truly hurt him. The Hourman sucker punches Sandy, knocking the creature out. Powerful tremors herald the occurrence of an earthquake. A crevasse opens up right beneath the Batman, the Hourman and the Sandman. The Elongated Man rescues the three falling heroes, while the Green Lantern clamps the crevasse shut. The Green Lantern, Superman, and Wonder Woman track the fault line beneath the sea. Superman sews the fissure shut with Wonder Woman's Lasso of Truth, then seals it with his heat vision. Sandy recovers. To the astonishment of all, Sandy is able to speak.
Sandy explains that early tremors awoke him from his slumber. From that point forward, he used his silicate form to absorb the tremors, to keep York City from being destroyed. Years of disuse had paralyzed his vocal cords, so that he could not inform the heroes of what his intentions were, nor could he allow them to stop him. Sandy reveals that he came to his senses fairly early on, after his transformation, but the Sandman's gas was so disabling he could never tell the Sandman. The Sandman falls into despair. Due to his actions, Sandy has been a prisoner for decades, wasting years of his life. The Sandman asks for forgiveness, then, crestfallen, walks away.
Aquaman, the Batman, the Green Lantern, and Superman reveal the story of the Freedom Train. In 1947, the train traveled across America, giving the populace a chance to see various historical documents, including the Constitution, the Bill of RIghts, and the Emancipation Proclamation.
This story was originally published in All-Star Comics #41 (June-July,1948). A plot summary for this story can be found at the link.
This story was originally published in Justice League of America #16 (December, 1962). A plot summary for this story can be found at the link.