Today we know that wearing blackface make-up is racist and it is not an acceptable thing to do. However in the early days of Hollywood white actors wearing blackface was very common. You may be surprised to see how many classic stars wore blackface in their films.
Judy Garland in Everybody Sing (1938)
Doris Day in I'll See You In My Dreams (1951)
Joan Crawford in Torch Song (1953)
Betty Grable & June Havoc in The Dolly Sisters (1945)
Marion Davies in Going Hollywood (1933)