The Pennsylvania Railroad Technical and Historical Society (PRRTHS) is a railroad historical society

Historical society

A historical society is an organization that collects, researches, interprets and preserves information or items of historical interest. Generally, a historical society focuses on a specific geographical area, such as a county or town or subject, such as aviation or rail. Many historical...

 founded in 1974 and organized as a Pennsylvania

Pennsylvania

The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...

 non-profit corporation and recognized as a 501(c)(3) tax-exempt organization by the United States Internal Revenue Service.
The Society defines its mission as bringing together those interested in the Pennsylvania Railroad

Pennsylvania Railroad

The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....

 and its predecessors and subsidiaries for the purpose of preserving and recording all information available about them.
The society is recognized as the source for PRR information by railroad periodicals such as RailModel Journal,
RailPace
and Model Railroader

Model Railroader

Model Railroader is an American magazine specializing in the hobby of model railroading. It was founded in 1934 by Al C. Kalmbach and is based in Waukesha, Wisconsin. It is published monthly by Kalmbach Publishing...

.

Publications

The PRRTHS has published a quarterly illustrated journal, The Keystone, since 1968. The journal contains researched articles on topics related to the PRR, as well as reader questions and answers, news items of PRR interest, and reviews of PRR-related publications.