William and Sarah BARTLETT lived on the Plantation in Fauquier Co, VA until at least 1785 - so all their children born before 1785, were born in Fauquier Co, VA. His father, Thomas c1733-1806, moved most of the family to Harrison Co, VA during 1785; but it appears William and Sarah remained in Fauquier - they sold the remainder of the Plantation there on 13 Feb 1790; and William is not in the Harrison Co, VA Personal Property Tax Lists until 1791; when he also bought land on Simpsons Creek. So I would assume all the children through Susannah b 1 Jan 1790 were born Fauquier Co, VA; and the rest of the children, beginning with Doratha b 16 Dec 1791 were born on Simpson's Creek, Harrison (later Taylor) Co, VA.