Seven Wise Dwarfs (1941)

7 Wise Dwarfs is an educational short animated film made by the Walt Disney Studios, and commissioned by the National Film Board of Canada, released theatrically on December 12, 1941 as a short film for educating the Canadian public about war bonds during World War II. The short features the seven dwarfs from Disney's Snow White and the Seven Dwarfs, four years after the characters made their screen debut. The short was released for the first time on home video in the Disney boxed set Walt Disney Treasures series: the 2 DVD On the Front Lines - The War Years. The DVDs were released in the 3rd wave of publishing of the Disney Treasures on May 18, 2004.

More at Wikipedia.