The Golden Age of US animation is a period in the United States animation history that began with the advent of sound cartoons in 1928 and continued into the early 1960s when theatrical animated shorts began losing to the new medium of television animation. Many memorable characters emerged from this period including Mickey Mouse, Bugs Bunny, Donald Duck, Daffy Duck, Goofy, Popeye, Tom and Jerry, Betty Boop, Mr. Magoo, Woody Woodpecker, Mighty Mouse and a popular adaptation of Superman. Feature length animation also began during this period, most notably with Walt Disney's first films: Snow White and the Seven Dwarfs, Pinocchio, Fantasia, Dumbo and Bambi. In 1923, after Walt Disney's previous Laugh-O-Grams cartoon studio went bankrupt, Walt moved from Kansas City to Los Angeles and lived with his brother Roy O. Disney who was working as a banker at the time. Walt was able to use an unreleased short entitled Alice's Wonderland as a pilot to sell to potential distributors. Alice's Wonderland was loosely inspired by Alice in Wonderland and featured a live-action 5-year-old girl named Alice (Virginia Davis) who had adventures in a fully animated world with her cat sidekick Julius.