From Wikipedia:

The Wizard of Oz is a 1939 American musical fantasy film produced by Metro-Goldwyn-Mayer and distributed by Warner Bros. Family Entertainment. Widely considered to be one of the greatest films in cinema history, it is the best-known and most commercially successful adaptation of L. Frank Baum’s 1900 children’s book The Wonderful Wizard of Oz. Directed primarily by Victor Fleming (who left the production to take over the troubled Gone with the Wind), the film stars Judy Garland as Dorothy Gale alongside Ray Bolger, Jack Haley, and Bert Lahr.

Characterized by its legendary use of Technicolor (although not being the first to use it), fantasy storytelling, musical score, and memorable characters, the film has become an American pop culture icon. It was nominated for six Academy Awards, including Best Picture, but lost to Gone with the Wind, also directed by Fleming. It did win in two other categories: Best Original Song for “Over the Rainbow” and Best Original Score by Herbert Stothart. While the film was considered a critical success upon release in August 1939, it failed to make a profit for MGM until the 1949 re-release, earning only $3,017,000 on a $2,777,000 budget, not including promotional costs, which made it MGM’s most expensive production at that time.

The 1956 television broadcast premiere of the film on the CBS network reintroduced the film to the public; according to the Library of Congress, it is the most seen film in movie history. It was among the first 25 films that inaugurated the National Film Registry list in 1989. It is also one of the few films on UNESCO’s Memory of the World Register. The film is among the top ten in the BFI (British Film Institute) list of 50 films to be seen by the age of 14.

The Wizard of Oz is the source of many quotes referenced in contemporary popular culture. Noel Langley, Florence Ryerson, and Edgar Allan Woolf received credit for the screenplay, but others made uncredited contributions. The songs were written by Edgar “Yip” Harburg (lyrics) and Harold Arlen (music). The musical score and the incidental music were composed by Stothart.