In 1928 Walt Disney's Steamboat Willie was released, making it the first Mickey Mouse cartoon presented in sound. Although, there's no dialog spoken, there is whistling and other vocal noises made by the characters and synchronized music. For the record, it's not the very first synchronized sound cartoon. Disney rival Max Fleischer had produced a series of sound cartoons featuring synchronized dialogue and music in 1926. But Steamboat Willie launched Disney (and Mickey) into the world of sound, and because of that it holds a special place in the hearts of fans.
According to Walt Disney's brother Roy, Walt came up with the idea of putting a soundtrack into his a Mickey Mouse cartoon after watching The Jazz Singer, which was released in 1927. On its release, the cartoon was paired with the movie Gang War (a 1928 release with no memorable stars). But it was this cartoon, not the main movie, that movie patrons walked away talking about. In fact, Variety's November 21 review of "Steamboat Willie" read: "Not the first animated cartoon to be synchronized with sound effects, but the first to attract favorable attention. This one represents a high order of cartoon ingenuity, cleverly combined with sound effects. The union brought laughs galore. Giggles came so fast at the Colony they were stumbling over each other."
Felix the Cat was the most popular cartoon of the movies at the time, but it didn't have sound and its creators were unprepared to make the transition as quickly as Disney. One of the animators, Hal Walker is quoted in John Canemaker's book, "Felix: the Twisted Tale of the World's Most Famous Cat" as saying, "Disney put us out of business with his sound". True enough. BY the time other animators caught up with the innovation of sound Disney had already secured a hold as the dominate force in sound cartoons. And as we all know, Disney never let the position alter.