Alice in Wonderland is a 1951 animated feature film produced by Walt and originally premiered simultaneously in the US and London, England on July 26, 1951 by RKO Pictures. It is the thirteenth animated feature in the animated features canon. Based on Lewis Carroll's books Alice's Adventures in Wonderland and Through the Looking-Glass; this adaptation solved the problems of the setting by using animation. The film features the voices of Kathryn Beaumont as Alice (also voice of Wendy Darling in the later feature film, Peter Pan) and Ed Wynn as the Mad Hatter. Made under the supervision of Walt himself, this film and its animation are often regarded as some of the finest work in studio history, despite the lackluster, even hostile, reviews it originally received, especially in the UK.