Hmmm... Though the dates are a little off, it sounds like you're talking about the 300 acres that William Elzey/Ellzey (son of Captain Lewis Elzey and father of the William Elzey I mentioned in my last e-mail) sold to Thomas Sangster, (blacksmith) in 1777.William Elzey was grantedthe land when he was a resident of Fairfax County in 1743.Elzey sold this land to your ancestor (along with another smaller parcel of land) when he was a resident of Loudon County, in 1777. (Fairfax County Deed Book M, pg. 252)
The location of this land is known and provable through a careful study of various documents, including the original 1743 patent (digital image online at the Virginia State Library), the later (1777) deed to your ancestor in the Fairfax County deed book, and a reconstruction of early land patents in Fairfax County (a meticulously researched map (circa 1760 snapshot) of how the tracts of land owned by the various grantees fit together) created by a researcher named Beth Mitchell in the 1970s.
My dad has the map and an accompanying book written by this woman.(The book, called “Beginning at a white oak…” was written in 1977 and went through a number of printings.You can probably get the bookthrough interlibrary loan at your local library, but the map-- which is not in the book-- is key.A picture’s worth a thousand words.)Also, there are other documents, such as the Fairfax County Road Orders andvarious newspaper clippings that give more info. about the Sangsters and their property (later neighbors, etc.)
Anyway, the 300 acres purchased by Thomas Sangster from William Elzey/Ellzeywas roughly a pentagon shaped piece of land with a leg at the bottom.From road names, etc. in the original land grant, it seems to have included Butts Corner (I think I mistakenly wrote “Buck’s Corner” yesterday, but it is Butts) at the intersection of Ox Road and Chapel Road in Fairfax County.(The place that was called Sangster’s Crossroads in the Civil War.)It also included the land where Sangster’s station used to be during the Civil War (now on privately owned property) and the Sangster family cemetery at 11200 Chapel Road.