There is a somewhat mysterious fellow, a David Buckner living in Pendleton District SC in 1800, which was up around that border area with Habersham, GA.
"United States Census, 1800," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XHRC-75R : accessed 7 December 2018), David Buckner, Pendleton District, South Carolina, United States; citing p. 117, NARA microfilm publication M32, (Washington D.C.: National Archives and Records Administration, n.d.), roll 50; FHL microfilm 181,425.
I don't really know who he is, but he was young and had three children at the time.