Complex sentence: His mother was a schoolteacher for several years; his father, who supervised a cotton-waste factory and established a trucking business, earned enough money to ensure that Southard did not have to work during his undergraduate and graduate studies.
Split into simpler sentences: His mother was a schoolteacher for several years, while his father supervised a cotton waste factory and started his own trucking business. His father made enough money to ensure that Southard did not have to work during his undergraduate and graduate studies.