Does Obama need to pay himself reparations How does this work Obama's ancestors on his white mother's side appear to have been slave owners. William Reitwiesner, an amateur genealogical researcher, has published a history of Obama's mother's family and discovered that her ancestors have a distinctly shadowy past. Reitwiesner traced Obama's great-great-great-great-grandfather, George Washington Overall, and found that he owned two slaves in Kentucky: a 15-year-old girl and a 25-year-old man. He also found out that Obama's great-great-great-great-great-grandmother, Mary Duvall, also owned a pair of slaves listed in an 1850 census record. They were a 60-year-old man and a 58-year-old woman. In fact, the Duvalls were a wealthy family whose members were descended from a major landowner, Maureen Duvall, whose estate owned at least 18 slaves in the 17th century.