In May 1941 the Fleischers gave Paramount full ownership of the studio as collateral to pay off their debts left from the loans they obtained from the studio to make unsuccessful cartoons like "Stone Age", "Gabby", and "Color Classics". However, they still maintained their positions as heads of their studio's production. Under Paramount rule, the Fleischers brought Popeye into the Navy and contributed to the war effort, and would gain more success by beginning a series of spectacular "Superman" cartoons (the first of which was nominated for an Oscar) that have become legendary in themselves.