The Keepers of the House by Shirley Ann Grau 1965

This is simply a great story and a great read about a wealthy, historic family in the segregated south. The Howlands have money but they don't show it. The tension becomes significant when the widower, William, "finds" Margaret, a poor black girl, and brings her home where she eventually bears his children. William also has a daughter and granddaughter from his first marriage (white), and the interaction between the family members weaves an interesting contrast in the times leading up to the civil rights movement. The Keepers of the House has a great climax and satisfying ending. I highly recommend it.