Walt was on the train, heading back to California. He was without a staff and without Oswald. He was so angry with himself for not knowing better than to retain the rights to a character, and heartbroken that something like this could happen.
He sat in his seat with a drawing of Oswald, staring at it for ideas. Legend says that it was then when a mouse scurried passed him on the train floor. Whether that is fact or fiction, it was then when he saw smaller, rounder ears on Oswald and altered the drawing to match, and a mouse was born. He had shown a new drawing of his new mouse creation. Three round circles made his head, and a long skinny tail protruded from the back of his shorts. He wore a great big smile and loads of enthusiasm. He had shown it to his wife asked what she thought of Mortimer Mouse. Lilly responded, "Mortimer? I think he looks more like a Mickey."
Having to re cooperate from the dastardly Charles Minzt, Walt vowed he would never trust his film rights to anyone again. He would distribute his films himself. If he needed funding, he would do so through bank loans.
Ub worked on whatever cartoons were in the pipeline, and while everyone left for the day, he'd stay late and work on the Mickey cartoons in secret. The first cartoon featured our wirey little mouse, learning to fly an airplane. He messed his hair to mimick Charles Lindbergh and grabbed his girl, Minnie for a fun filled flight. This zany cartoon would be titled "Plane Crazy". It was fantastic to see.
The cartoon was one visual gag after another. Mickey flew in loops and barrel rolls, all done in rubber hosed animation, utilizing all the benefits of squash and stretch fashion. While the animation was in the process of ink and paint, they followed this cartoon with "The Galloping Goucho". Animating feverishly to complete it for release until something was to happen to Hollywood and change the game forever. Sound. Walt saw the first "The Jazz Singer" and knew then what he needed to do. He had seen a Buster Keaton film called "Steamboat Bill" and saw it perfect for parody. He imagined Mickey, captaining a steamboat, and how amazing it would be to showcase the first animated short cartoon utilizing sound. His other two cartoons would be shelved for the time being, and they crew continued full steam ahead on this new adventure for Mickey.
"Steamboat Willie" premiered at the Colony Theater in New York on November 18, 1928. Walt and a small team of his staff performed music, sound effects and character sounds. (Walt provided the voices of Mickey and Minnie, and would continue to perform Mickey's voice until 1947) The short was a huge success. Walt took the two shelved cartoons and added sound to those as well. Mickey mouse would soon become a household name, and the Disney Brothers cartoon studio was on it's way to great stardom.