Mickey Mouse in "Steamboat Willie"

Steamboat Willie (1928) is an animated cartoon released on November 18, 1928. It was the first Mickey Mouse sound cartoon (Mickey had appeared in two earlier cartoons, Plane Crazy and The Gallopin' Gaucho). It was also the first Disney cartoon to feature synchronized sound. Disney used Pat Powers' Cinephone system, created by Powers using Lee De Forest's Phonofilm system without giving De Forest any credit. Steamboat Willie premiered at New York's 79th Street Theatre, and played ahead of the independent film Gang War. Steamboat Willie was an immediate hit while Gang War is all but forgotten today.

http://www.youtube.com/watch?v=0TPbpvP-okM