De Pillis specializes in the history of such groups as the Mormons and Shakers .
Mario S. De Pillis ( born 1926 , in Philadelphia , Pennsylvania ) is an emeritus professor of American Religious history at the University of Massachusetts Amherst .
Mario S. De Pillis   specializes in the history of such groups as the Mormons and Shakers .
Mario S. De Pillis ( born 1926 , in Philadelphia , Pennsylvania ) is an emeritus professor of American Religious history at the University of Massachusetts Amherst .