Delaware County
Delaware County History http://www.delawarecountyhistory.com
Chester Historic Preservation Committee http://www.delcohistory.org/chester
Darby Borough Historical and Preservation Soceity http://www.delcohistory.org/darby
Delaware County Archives http://www.co.delaware.pa.us/depts/archives.html
Delaware County Heritage Commission http://www.co.delaware.pa.us/planning/heritage.html
Delaware County Historical Society http://www.delawarecountyhistoricalsociety.org
Delaware County Institute of Science http://www.delcohistory.org/dcis
Delaware County Library System http://www.delcolibraries.org/Databases_History.htm
Haverford Township Historical Society http://www.haverfordhistoricalsociety.org
Old Chester PA http://www.oldchesterpa.com
Springfield Historical Society http://www.delcohistory.org/shs
Other Local Counties
Bucks County Historical Society http://www.bucknet.com/bchs
Chester County Historical Society http://www.chestercohistorical.org
Lancaster County Historical Society http://www.lancasterhistory.org
Montgomery County Historical Society http://www.hsmcpa.org
Pennsylvania
Historical Society of Pennsylvania http://www.hsp.org
Pennsylvania Historical and Museum Commission http://www.phmc.state.pa.us
Pennsylvania Vital Records Information http://www.vitalrec.com/pa.html