Death certificate says 1864, but that is inconsistent with census records throughout his life, as well as the record at Find A Grave (although there is no stone photo, so it's unclear where that date came from).
1900 Hardin Co, TN: William Jul 1861 TN, m 5 yrs; Lizzie Jun 1874 TN 4 kids, 3 liv; Mary M. Feb 1896, Akero (son) Apr 1897, Willie (dau) May 1899 (Dist 5, p 107, 6/5/1900)
1910 Hardin Co, TN: William B. 48 TN, par TN; Lizzie 35 Tn, m 15 yrs; 7 kids; Mary M. 14 TN; Jeff A. 12 Tn; Willie S. (dau) 13, Thomas A. 9 TN; Ben M. 7 TN; Bob H. 4 Tn, Cynthia H. 3 TN (9-Dist, p. 161, 4/29/1910)