Came across your old posting while looking for connections to my Low family. I have a William P Law in Wythe County, Virginia on April 13, 1802 being granted a license to practice law by the Court of Wythe, VA. He again appears on June 8, 1802 serving on a jury. This is the only one I have come across for Wythe Co. There were many Laws in Wilkes, North Carolina in late 1700's and early 1800's. Since you had a William P Law in your family I thought this might be of interest to you.
Karen