Marvelous Miniature Mighty Men & Maidens

In 1943 on the world known as Earth-S, the young hero known as Captain Marvel Junior met a tribe of miniature men and maidens which is labeled the Trolls. They were the same hidden dwarfs as were those encountered previously by Captain Marvel shortly before this. They were their universes version of the Kandorians of Earth-One, who were originally Kryptonians of Krypton-One who were shrunk by the android Brainiac and kept in a jar until located by Superman. On Earth-Two, the mini Kandorians were actually virtual reality copies of the now long dead Kryptonians

Just as the Marvel Family had connections to their Trolls, so had the Superman Family with Kandorians. After securing them for his foe, Superman brought them to his Fortress of Solitude where several of these Kandorians aided him later as the Superman Emergency Squad. 

Similar miniaturized humans were found in Midget Town. While a chemical formula was used by Darrell Dane to transform into the 6 foot tall Doll Man in 1939, in the early 1940s the malevolent mastermind known as Brain Wave developed a purple ray which accomplished this feat. A variation of these treatments was later used on a village by another criminal scientist named Doctor Vargo. Doll Man became aware of these tiny folk, causing them to turn on their creator Thinking this town was destroyed, Dane never revisited it, as it developed into the more civilized Midget Town within a few short years