In 1940, when the first Oscar for Special Effects was awarded, the winner was neither The Wizard of Oz nor Gone with the Wind. Although both of those motion pictures were nominated for the then-new Academy Award for Special Effects, the trophy was given to Edmund H. Hansen, Fred Sersen and Roger Heman, Sr. for The Rains Came. This Myrna Loy film was nominated for six Oscars, but walked away with only one.
At the time, visual and sound effects were lumped into the same category. After the Academy came to the conclusion that the film with the best sound effects did not necessarily feature the best visual effects (and vice versa), the Special Effects category was split into those two divisions beginning with the 1963 ceremony.