​Born in 1946 and raised in the Chicago area, Dr. Karen Nagel studied history at Southern Methodist University in Dallas, Texas. After college, Nagel moved to the Baltimore area, where she earned her PhD in Human Growth and Development from the University of Maryland. In 1986 Nagel moved to the Main Line outside of Philadelphia, where she went on to become an accomplished architectural historian. For the past 30 years, Nagel was a passionate preservationist who created historic districts, national trust nominations, and countless dossiers of historic houses throughout the Main Line. She helped create the Avon Colorado Historic Commission and was a founding member of the Lower Merion Preservation Trust (now the Lower Merion Conservancy). She received a Preservation Award from the Historic Architectural Review Board of Lower Merion Township for various buildings and efforts supporting preservation. Among the historic properties that Karen helped save was the Gerhard Building of Bryn Mawr Hospital, designed by Frank Furness. Dr. Nagel passed away in 2024.