An influential American animator and director, he is best known for his work with Walt Disney Productions during the 1930s and 1940s. He played a significant role in directing classic animated features like "Snow White and the Seven Dwarfs" (1937) and "Bambi" (1942). He contributed to the development of the Disney storytelling style and animation techniques. Later, he became involved with Gaumont British Animation, helping to shape the animation industry in the UK.