Dear David, As several others have said, I also believe you should be open to many spelling variations. I have a Peter J. Blenkensop, b. c1781 d. 1857 in Madison, Jefferson Co., IN. His daughter Theresa is listed in later census records as Theresa M. J. Blankenship. Other Blankenship families lived in the same area at the time, although no proof exists to connect them, the dates make him a good fit to be a brother, in spite of the different spelling. The above Peter's widow moved to Memphis, TN where she died in 1860. If either of these locations is a match, you might want to check this Peter. Send in your dates and locations and we may be able to help you. Pat T.