Lady and the Tramp is a 1955 American animated romance film produced by Walt Disney and released to theaters on June 22, 1955, by Buena Vista Distribution, making it the first Disney animated film to not be distributed by RKO Radio Pictures. The fifteenth animated feature in the Disney Animated Canon, it was the first animated feature filmed in the CinemaScope Widescreen film process. The story, which was based the book Happy Dan, The Whistling Dog by Ward Greene, centers on a female American Cocker Spaniel named Lady who lives with a refined, upper-middle-class family, and a male stray mutt called Tramp. A direct-to-video sequel, Lady and the Tramp II: Scamp's Adventure, was released in 2001. While not a runaway hit at first, today it is considered one of Disney's greatest classics.