Known thus far, these are the lines immediately related to us, (as in my parents and siblings,) having surname Thornton: 

• Paternal and agnatic line going back.  As delineated on the webpage Agnatic Thornton pedigree, James Thornton the second, and his father LTC Dr. James Thornton, who practiced dentistry in New York, and his father Civil War Veteran Thornton, who was from Leesburg, Virginia and settled from the time he was about in his 20s onward in Raleigh, Wake, North Carolina. Records of who the father of the Civil War veteran are, have been obtained, however not stated here at this time (January 2021).

• David Johnston, later Johnson, who some records show was from Virginia, who moved to Alabama, his wife was nee Thornton. 1800s era. Confer webpage discussing Johnson, at A few of the families... studies underway.