What is a short summary of Parts IV and V in the nonfiction book, The Warmth of Other Suns?

Part Four: “The Kinder Mistress” describes life in the new destinations of the three migrants. In many cases, their new “mistress” didn’t live up to expectations but it was “kinder” than their former mistress. The use of the word “mistress” implies that the black migrants were still under the thumb of a society that favored whites. Part Five: “Aftermath” contains the final interviews that Wilkerson conducted with the three migrants. They were old and near the end of their lives and reflected on the choices they made.