Ancestors of William Thornhill, b 1735

     I have searched many years for the ancestors of  Revolutionary War Veteran William Thornhill, who fought at the Battle of Cowpens and who resided in Bedford County, Virginia. His wife was Sarah, maiden name unknown. They had eight children: William, Ezekial, Rachael, Briant, Edna, Sally, Leonard and James. Virtually all of the researchers I have communicated with over at least thirty years have maintained that William was born in Maryland. In fact, it was stated that William had actually made such a statement. How that could be known I have no idea. No one that I am aware of  though ever found his parents there or, as a matter of fact, any where else-- up until now.
     Just within the last month I received information stating that William was not born in Maryland but in Rappahannock County Virginia to Bryant Thornhill b1705 also in Rappahannock Coutny, Virginia and _______ Thompson. Bryant was the son of Bryan Thornhill, the immigrant, who was  born abt 1670 in Yorkshire, England and Elizabeth Phillips.
     It is interesting to note that William named his third son Briant . The second son was named Ezekial. Could  that have been his wife Sarah's father's name?  As an interesting aside, I've seen three spellings, Bryant and Briant and  Bryan for the family name. I haven't the vaguest notion which is correct. Maybe all three were used to help determine which was which. I do suspect, however, that all will be found to have the same name, Bryant or Briant or Bryan. As the old saying goes, "you pays your money and you takes your pick."
     I would really appreciate some input on this family lineage.