Directed by: Victor Fleming
Starring: Frank Morgan, Judy Garland, Billie Burke, Ray Bolger, Bert Lahr, Jack Haley, Margaret Hamilton
Continuity mistake: When the Wizard is in the balloon, he raises his top hat pointing in an 11 o'clock direction. A frame later it's pointing in a 9 o'clock direction.
Continuity mistake: When Dorothy and the Scarecrow find the Tin Man and oil his mouth, between shots, the leaves on the Tin Man's shoulders change.
Revealing mistake: During some scenes, straw-stuffed Scarecrow's pant legs and his boots would sometimes have a gap that reveals the skin of Ray Bolger's leg. Two examples are, at Emerald City when Scarecrow places Lion's "cape" on him, and also when Dorothy and her friends are told the Wizard says to go away. (01:05:50 - 01:07:25)
Wicked Witch: Ohhh... You cursed brat! Look what you've DONE! I'm melting! Melting! Oh... What a world, what a world! Who would have thought a good little girl like you could destroy my beautiful wickedness?!
Trivia: Professor Marvel, the Cabbie, the doorman, the guard, and the wizard himself are all the same actor, Frank Morgan.
Question: Did Dorothy really go to Oz or was it a dream? Because, in return to Oz at the end, she sees Ozma (the good witch in her mirror) or was that just her imagination/a dream too?
Answer: Return to Oz was not a direct sequel to the 1939 film. One was developed by Disney and the other by MGM. Return to Oz is actually an adaptation-fusion of the second and third Oz books, that contains elements from the 1939 film (like the Ruby slippers and the Oz/Kansas counterparts) because that's what people are most familiar.
Answer: In the film it's left ambiguous. At the end it's strongly implied that she was dreaming. The characters she meets all look like people she actually knows. In the original book, she actually went to Oz.