1880 US Census has William B Davis living in Cincinnati, married to "Francis C Davis", which is actually Frances R. Clark.
They have children William L, and Clark W.
Living in the house is his mother-in-law, Mary J (Redman) Clark, now 60 and widowed, and Jessie (Jesse) Clark her son, brother-in-law to William.
These details can be read on the original copy via Ancestry.com.
Record via FamilySearch.
Accessed 10 April 2015.
abt. 1880