His most popular films were `` The Wizard of Oz '' ( 1939 ) , and `` Gone with the Wind '' ( 1939 ) , for which he won an Academy Award for Best Director .
His most popular movie were `` The Wizard of Oz '' ( 1939 ) , and `` Gone with the Wind '' ( 1939 ) . He won an Academy Award for Best Directing in 1939 .