I just located a marriage record for Jane Holmes and William V. Athy, married in Clark Co. Ohio on July 3, 1866. William b.1827 OH and Jane b.1828 England. Could this be your William?
Listed in the 1870 census, Madison Township, Clark Co. Ohio are William Holmes b.1821 England, wife Elizabeth b.1830 PA and children. Also a Mary Holmes b.1800 England is shown living in same Township with daughter Mary A. Paist b.1825 England.
I believe William V. Athy's father may have been Henry Harrison Athey b.1815 Bourbon, Kentucky d.1893 Putnam, Indiana. I have Henry's lineage if you think this ties in.