What is the theme in Ethnic America: A History by Thomas Sowell?

Sowell sets out to describe the complexities of ethnic groups over and above their differences within themselves and better each other. Ethnic groups have complex histories that vary significantly. Blacks not only suffer from a legacy of slavery but from a resistance to embracing values that would help them progress in American society. The presence of West Indian blacks is often ignored or obscured in the history of black American.