William Dillon Family

Looking for more info on this family. William Dillon Sr., wife Sarah Spencer, came to Belmont Co., OH about 1829. He and his one son, Dr. William Dillon, later moved to Monroe Co., Ohio, I think between 1850 and 1860.
Dr Dillon says he was born in Louden Co., Virginia in 1827. We have not been able to trace his parents any further back, except for on census record in which the father, William says he was born in Virginia? about 1790.
We have good info forward from about 1860, but can't go back before 1800.
Janet