This collection contains minutes of the Society, 1781-1975; minutes of the directors of the Corporation, 1929-1947; membership book (with signatures of early members), 1785; and names of later members. There are also deeds to the meeting house and burying ground; treasurers' accounts; reports of officers and committees; bills and receipts for constructing, maintaining, and repairing the meeting house; cancelled checks; and letters to the Society and its officers, especially Samuel Wetherill, 1883-1884.

Working on the Army Epidemiological Board in the 1940s, Joseph Stokes, Jr. discovered the value of gamma globulin for the prevention of epidemic hepatitis. His subsequent research included immunization against influenza, protection against poliomyelitis by gamma globulin, antigenic difference between epidemic and serum hepatitis, immunization procedures in mumps, development of a vaccine against measles. His clinical focus was on the causes and prevention of childhood infectious diseases. His administrative work includes the transformation of Children's Hospital of Philadelphia and the University of Pennsylvania, School of Medicine, Department of Pediatrics. His community work consists of public health and environment control issues.