10. Judy Garland was the first choice by the producers for the part of Dorothy
It is often reported in various venues that Judy Garland was not the first choice to play Dorothy, (who in the books is a twelve-year-old Kansas farmgirl) and that the producers preferred Shirley Temple. The opposite is true; producers Mervyn LeRoy and Arthur Freed made clear that their first choice was Garland, who was sixteen when production began. Louis B. Mayer, head of MGM, suggested that Garland was too old and too developed physically for the part, and offered to check on the availability of Temple, who was under contract with 20th Century Fox.
Garland had by then made several films for Mayer and MGM, often alongside Mickey Rooney, and the success of their partnership led Mayer to do what he could to ensure that she retained her youthful appearance. He applied the same rules to the set of The Wizard of Oz, restricting her diet (she lost 17 pounds during the production), having her wear corsets designed to hide her figure, and even having her famous gingham dress designed to keep her looking younger. At one point she was encouraged to take up smoking to help curb her appetite, and in later life, she claimed that Mayer had provided amphetamines for the same reason.