The Mifflin County Historical Society, founded in 1921, had become known as "Frysinger' s Dream". The founder George R. Frysinger had served as a Civil War editor of the Lewistown Gazette and ended his years of affiliation with the Society as the President Emeritus.

The Constitution of the Society states: "exists to record and preserve our history and to relate to present day events and places, that coming generations will cherish and protect this heritage from the past and its people".

The Society welcomes the membership of all in accord with its purpose - natives, newcomers, residents of the area, or those living far away.

The annual dues structure includes individual, family, supporting, civic or social & business organizations. There is a category for life membership and gifts and bequests are gratefully received. Membership dues are based on the calendar year.

The Society operates primarily through the support of member volunteers. They research all genealogical requests for the library and change and update displays for the museum. They conduct tours of the museum and assist patrons in the library. Volunteers maintain regular "open" hours and accommodate special requests for both library and museum use. The Society secretary, whose office is in the Old Courthouse, coordinates activities of volunteers in the two branches of the Society as well as attending to regular business. Volunteers for both museum and library work are always needed. Interested members should contact the office.

Programs and trips are scheduled by the program committee throughout the year, and the annual dinner meeting with business, elections and program is held in April. An informative news letter is mailed throughout the year.