Mary Duke Biddle Trent Semans, heiress to a fortune built on tobacco and member of the family that founded Duke University, died Wednesday at age 91, the Associated Press reported.

A resident of Durham, N.C., she was the great granddaughter of Washington Duke, a former Confederate soldier who became a tobacco farmer and helped build the popularity of cigarettes, the AP reported. He also endowed a Methodist college that became Duke University. (pi)