Melva: I am just now re-reading this and think I can help. I have studied and researched the Duncans for years and have a hard time keeping them apart since they moved quite a bit and named children the same names over and over. This is what I have:
William Duncan married Frances Benson (divorced in the 1840's) and had 5 children. In 1823, William Duncan was appointed sheriff. In 1820, William and son Asahel are on the same census page in Darnells parish, Caldwell, KY:
1. Samuel married Sarah ______
2. Asahel (1779-1858) married 1) Sarah Anderson in 1802 and had:
• Elizabeth married John Wilson Frizzell and moved to Texas in 1866
• Sarah (Sally) who married Thomas Gregory
• Samuel married 1) cousin Elizabeth and 2) Ruahana Frizzell
• Emily Jane
• Nancy married 1) Thomas Duncan and 2) Isaac Gray
• William married Sarah Bourland
• John married Malinda Thelford
• Celia married William Frizzell
• Lewis married Sally Lynch
• Crawford Anderson Duncan (1814-1882) married Elizabeth Harvey in 1838 and after a stint as sheriff of Calloway County, moved to Madison County, TN.
• Asahel married 2) Nancy Jennings Grubbs in 1826 and had son Samuel, born
3) Andrew (1780-1848)
4) Elizabeth married Samuel Duncan (her cousin was the son of Asahel and Sarah A. Duncan). When she died, he married Ruahana Frizzell in 1841.
5) Lewis married Hannah Holcomb
Please let me know if I have any errors in this information. Also, I need more information on Harvey family (there are 6 Harveys in Hardeman County, TN who are listed in marriage records from 1823-1850. I would also like to know the ancestors of William and Frances Benson Duncan.