Question

k" during a period of widespread racial discrimination in the United States. Why might the wearers of the mask not want people to see their pain?

Answer 1

During the hard time that the black people had in America late 19th, they were masks that simulating happiness, if they reveal their true feeling of pain, defeat and desperation about the mistreatments received from the white people they would risk themselves to serious and dangerous consequences.  

Answer 2

Concern for their own safetythe fear of appearing weakthe belief that the world wasn't ready to see itthe feeling that revealing pain would hinder their success