Douglas, what was the original 'black face' intent?    

I think of the more clownish mask.   I think of it in relation to theater and movies that are fantasy/entertainment and don't show the lives of most blacks citizens in America.      It might mean the loss of jobs and income: Why shouldn't a black actor play a black person.   
It is white people stereotyping black Americans in a way that is clearly dismisses black people as equals to the white?  

*I  remember such thought as a white child in Texas.    In 1960 Houston, there were few black people in main stream professions.   Pretty sure I assumed  it was because black people couldn't do those jobs- ever- they couldn't learn.  I was only 7 years old.   Indoctrination starts early, when a child only knows/believes what they are told by family or neighborhood.      Some children have experiences that change that internal racial bias, some children never question that bias.

Good to hear a black voice, I hope you keep writing.