You didn't actually think Walt Disney gave up that easily, did you? During the year 1928, Walt release a mini animated film called "Steamboat Willie" featuring the one and only, Mickey Mouse! This was the first time Mickey Mouse had appeared in a film, as well as the first time an animation film had sound. Undoubtedly, it was a hit immediately.
We sometimes see "Steamboat Willie" as the trademark clip of Walt Disney in Disney films.