He is listed as Jno W. Clem with Martha in the 1840 census for Clark Co, KY, both 20-30 with a boy and a girl under age 5.
The 1850 census shows John W. (31, KY) and Martha Ann (25, KY) Clem. Their children included Mary J. (12), Wesley (10), Pamelia (8), Francis (6), and A. T. (male, 4) and John (1).
In 1860 his family consisted of John Clem (44, KY) a carpenter, wife Martha A. (40, KY) and children Wesley B. (20), Permelia (18), Francis M. (16), Tandy (14), John (12), Barbary (10), Waller (6), and Colby (3); all born in Kentucky.
The family is listed in 1870 as John Clem Sr (59, KY) a carpenter, wife Martha (58, KY) and children Tandy (23), John Jr (21), Barbara (18), Waller (14), and Coleby (12). Son Wesley and his family are listed next below them.
They are listed again in Fayette Co, KY in 1880, ages 66 and 61, with just their two youngest sons, Waller (25) and Quisenbury (Colby) (22).
[Obituary] Leader - 9 Feb 1903
The funeral services of Mr. John Clem, 86, took place at the Cemetery Chapel this afternoon. Mr. Clem was the father of Walter and Colby Clem.