Its my understanding that Moses Pendergraft (1793-1850), husband of Margaret Mashburn, probably changed the spelling. His brother Thomas also changed but some of their siblings didn't. The father of Moses and Thomas was Joseph Jobe Pendergrass (1753-1831). According to information I have seen on the Internet there are at least eight ways to spell the name and all are related to James the Immigrant (1640-1718). Both Mary Pendergrass and Larry Pendergraft have very good web sites on this family. My ggrandfather is Wesley Powell Pendergraft (1828-1893) son of Moses Pendergraft (1793-1850).