why does Richard's mother keep avoiding his questions about white people? what does he learn about his own family history?

Racism isn't a topic mother wants to address. Curiosity is something the whites fear because it can lead to uncovering the truth about what fuels their racism. This fear is passed onto the blacks they have power over. Mother does not want any trouble her boy may cause by asking too many questions. Richard learns that his life resembles that of sharecroppers in the Jim Crow South. He lives in depression era Chicago in a cramped apartment in a white man's building and on a white man's land.