Julius S.F. Pendergraft was my gr-gr-grandfather's brother. According to the records I have, his eldest son was named William Sanford. He had a younger brother named Samuel Cornell, which may account for some of the Samuel Pendergrafts you're finding records for. Or it could be that they both went by their middle names and "Sam" was a nickname for the elder brother. Cornell (pronounced "char-nell") was a very common given name in the family.