Pennsylvania Center for the Book
Pennsylvania History Library Research Guide
Penn State History Program at University Park
Penn State Special Collections Library
Explore PA History A set of documents and essays centered around PA's state historical markers.
Pennsylvania's Documentary Heritage Contains rare and important original documents from the Pennsylvania State Archives.
Balch Institute of Ethnic Studies
Carnegie Library of Pittsburgh, Pennsylvania Department
Centre County Historical Society
Historical Society of Pennsylvania
Historical Society of Western Pennsylvania Library & Archives
National Archives - Mid-Atlantic Branch
Pennsylvania Historical Association
University of Pennsylvania Libraries
University of Pittsburgh Library
The PA State Library maintains an extensive list of libraries in Pennsylvania
Keystone Treasures: A Guide to Museum and Historical Organizations in Pennsylvania
