The 1900 census shows the people you are talking about as living in West Finley Twp. Living right door is H. B. Carroll, born Oct 1843. Listed with him is his mother widowed Rebecca born June 1808. The 1880 census lists John H. Carroll 41. Anna 30, Myra 2, Bessie 3/12 and his widowed mother Rebecca 72. The 1870 census shows John Carroll 67, Rebecca 62, Hamilton B. 24, etc still living in W. Finley. The 1860 census has the family again in W. Finley. The 1850 census has the family in E. Finley under the spelling of Corroll.
Check with the Washington County Historical Society, Washington Family History Center and the Genealogical Society of Southwestern Pennsylvania to see if they can help you. I suggest getting the death certificates of key people to confirm the lineage. Obituaries can also be quite helpful.