Simplify the following text for a Grade 6 native English-speaking person.
Original: McDaniel is probably best known for her role as Mammy in the 1939 movie , Gone with the Wind where she won a Academy Award for Best Supporting Actress making her the first African-American to win a Academy Award .
Simplified: She won the award for Best Supporting Actress for her role of Mammy in Gone with the Wind ( 1939 ) .