Trivia: "Over the Rainbow", which the American Film Institute recently named the greatest movie song of all time, was nearly cut from the film.
Trivia: During filming, Toto was accidentally stepped on by one of the Witch's guards, and had to be replaced for several days with a look-alike. Other on-set accidents included two winged monkey actors who fell when their support wires snapped, and Margaret Hamilton being severely burned when the elevated platform that made her disappear from Munchkinland in a puff of smoke malfunctioned.
Trivia: The coat that Frank Morgan wears as Professor Marvel was bought second-hand for the film. It was only discovered later that it once belonged to L. Frank Baum, the creator of the Oz stories. The name sewn into the garment was shown to his widow, who confirmed that the coat did indeed once belong to the author.
Trivia: Buddy Ebsen, the original actor hired to play the Tin Man, became very ill from the metallic makeup and was not able to appear in the movie, but his voice can still be heard singing "We're off to see the wizard," when Dorothy and her friends are dancing down the yellow brick road after the forest scene.
Trivia: In L. Frank Baum's books, Dorothy was actually about 11 years old. As Judy Garland was in her mid-teens when she was cast, MGM pulled out all the stops to make her look as young as possible. Already on a chicken soup-only diet and appetite suppressants (as she was a little too chubby for the studio's liking), MGM upped her dosage and had a corset made to flatten any signs of a womanly figure. Garland had to have special lessons on how to walk, talk and dance normally as the corset was so tight. The costume department dressed her in a childish pinafore dress and gave her little girl plaits too. Even with these efforts it's still clear to see that Garland looks older than 11 in the film.
Trivia: The method used to make the house fall: Paint the sky on the floor, hold a toy house up against the camera which is elevated over the floor, film the house falling, then reverse the film. Voila.
Trivia: Some of the more minor mistakes in the film may have been left in because there was no time to shoot more accurate takes. This picture wasn't expected to be as big of a hit as it was, and when it went over-budget and took longer than expected to shoot, a lot of pressure was put on the crew and director to finish it. MGM wanted to put Judy Garland in a film with Mickey Rooney, as he was a bigger star than she was (and the studio thought starring with him would help her career), so the crew of the film had to rush to get it all shot and edited so Garland could be released. There was also pressure as every Technicolor camera in existence at the time was needed for Gone with the Wind, which had already started filming.
Trivia: Originally, the Wicked Witch of the West recorded a lot more scenes. Most of these scenes were cut because the director thought it would scare the children too much. You can see evidence of this when the foursome are surrounded by her guards and the witch comes and says something like Ring around the Rosie and it cuts to a different scene with her in it. (01:28:00)