I purchased the subject undated photo of a middle-aged man and an elderly man identified on the back of the mount in period ink handwriting:
"Gabriel F. Keath in his 80th yr and son George."
These individuals appear in Public Member Trees posted on ancestry.com.Gabriel is listed in the 1850 Census data for District 7, Boone Co., KY; the 1870 Census data for Ash Grove Township, Iroquois Co., IL; and the 1880 Census data for Belmont Township, Iroquois Co., IL.
Gabriel Farrow Keath, born 12 Mar 1819 in Montgomery Co., KY, died 14 May 1899 in Iroquois Co., IL, was the son of Gabriel Farrow Keath (1781-1833) and Deborah Case (1784-1864). He married three times and had a total of 15 children. The younger man in the photo, George Lincoln Keath, born 5 Nov 1864 in Iroquois Co., IL, died 1948 in Ash Grove, Iroquois Co., IL, was the son of Gabriel's third wife, Mariah Moore (1839-1936).George married Maud L. Honnold (1878-) and the couple had 5 children.