"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MMNQ-FRH : accessed 8 January 2017), Martin Sexton, Elk Creek District, Grayson, Virginia, United States; citing enumeration district (ED) 40, sheet 8B, family 146, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,241,710.
This looks like him in the 1900 census. There are several Sexton families on this sheet. I saw a Stephen on the page before the one he is on.
I was hoping to find a Lorna but I didn't. Probably just adding to your brick wall but I suspect this is a sister
Virginia Marriages, 1785-1940," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:XRZC-JN1 : 5 December 2014), Will Duncan and Lorna Sexton, 09 Nov 1904; citing Grayson County, Virginia, reference reg2 p112 #141; FHL microfilm 31,758.