The Society operates the Mather House Museum. Several historical structures, including the 1840-1860 Mather House, house exhibits related to local history, including displays of toys, spinning wheels, and quilts; a collection of items from old-fashioned barber shops, general stores, and butcher shops; Port Jefferson shipbuilding and sailmaking artifacts; and antique clocks.

The museum offers exhibits, tours, and occasional recreational and educational events.