Complex sentence: His maternal grandfather, renamed David Greer, was imported as a slave to South Carolina but, according to family tradition, people noticed he had royal Mandingo marks and did not sell him into slavery; he worked for a Quaker family.
Split into simpler sentences: His maternal grandfather, renamed David Greer, was imported as a slave to South Carolina. According to family tradition, people noticed he had royal Mandingo marks and did not sell him into slavery; he worked for a Quaker family.