History and Genealogy of Mercer County, Pennsylvania Cities within the county include: Farrell Hermitage Sharon The county seat is: Mercer Welcome to Mercer County, Pennsylvania Part of the Genealogy Trails History Group Volunteers dedicated to putting Historical and Genealogical information online for the FREE use of all researchers. Mercer County is located in northwestern Pennsylvania, along the Ohio border. Mercer's adjacent counties are: Crawford, Venango, Butler, Lawrence, Mahoning (Ohio), Trumbull (Ohio) Mercer County was created from Allegheny County on March 12, 1800. Source: Wikipedia Early History Biographies Census Records Buroughs, Townships & Census-Designated Places Surnames Military Old Photos Obituaries   Mercer County Marriage Records Cemeteries     Mercer County Newspaper Excerpts   Latest UPDATES to this site! Mercer County Volunteer Host Denise Burge We welcome your contributions! Regretfully we are unable to perform personal research. Return to the Pennsylvania state page Visit the Genealogy Trails main page Search The State Of Pennsylvania (Or search all of the Genealogy Trails state pages here.) State Selection: AL AK AR AZ CA CO CT DC DE FL GA HI IA ID IL IL IN KS KY LA MA MD ME MI MN MO MS MT NC ND NE NH NJ NM NV NY OH OK OR PA RI SC SD TN TX UT VA VT WA WI WV WY Advanced Search Powered by FreeFind Copyright © Genealogy Trails All data on this website is Copyright by Genealogy Trails with full rights reserved for original submitters.