William was born in 1826. William Davis ... 
1870 Census Elkton, Hickory, Missouri
Head: William Davis 43 Born in Kentucky
Female: Manerva 33 Born in Tennessee
Male: T Granvill 10 Born in Tennessee
Male: Christopher C 8 Born in MIssouri
Female: Mary Jane 6 Born in Missouri
Green, Hickory, Missouri
Head: William N Davis 54 Born in Kentucky
Wife: Minerva J 44 Born in Tennessee
Stepson: Thomas L Glanvill 20 Born in Missouri
Stepson: Christopher C Glanvill 18 Born in Missouri
Stepdau: Mary J Glanvill 16 Born in Missouri
Dau: Hanah L Davis 8 Born in Missouri
Dau: Virginia D Davis 7 Born in Missouri
Dau: Susan R Davis 4 Born in Missouri
Dau: Nancy E M Davis 2 Born in Missouri
Father In Law: Lawrence B Wells 72 Born in Tennessee
"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M6XW-WWR : 7 September 2017), William N Davis, 1880; citing enumeration district ED 238, sheet 508D, NARA microfilm publication T9 (Washington D.C.: National Archives and Records Administration, n.d), roll 0690; FHL microfilm 1,254,690.
It may be possible to confirm family relationships with William by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with William: