General Railway Signal Company supplied railway signaling equipment, systems, and services. In 1904, it was formed by the merger of three companies and was headquartered in Rochester, New York. This small collection of photographs showcases the company's work installing centralized traffic control systems, light signals, and car retarder systems.

The Pennsylvania Railroad Company was the largest railroad in the United States in terms of corporate assets and traffic from the last quarter of the nineteenth century until the decline of the northeast's and midwest's dominance of manufacturing. These records provide nearly comprehensive coverage of corporate matters for the entire time span and reasonably complete coverage of the functional departments from 1920 to 1950, with less coverage from 1893 to 1920 and from 1950 to 1968.

The Reading Company, chartered in 1871, became the holding company for the system of railroads, canals and coalmines assembled between 1833 and 1896 by its predecessor, the Philadelphia & Reading Railroad Company. The collection consists of photographs [negatives, blueprints and other graphic materials relating to the Reading Company and its predecessor, the Philadelphia & Reading Railroad Company.

The Reading Company, chartered in 1871, became the holding company for the system of railroads, canals and coal mines assembled between 1833 and 1896 by its predecessor, the Philadelphia & Reading Railroad Company. The collection consists of graphic materials relating to the Reading Company and its predecessor, the Philadelphia and Reading Railroad Company

Red Arrow Lines, Inc. was a suburban transit company. This collection contains photographs of Red Arrow Lines transit vehicles and stations that were used in book R. DeGraw, Red Arrow Lines.

Chartered in 1869, the Wilmington & Western Rail Road Company formed to create a rail line connecting Wilmington, Delaware, with Landenberg, Pennsylvania. A non-profit organization, Historic Red Clay Valley, Inc. (HRCV)., formed in 1960 and today operates the line as a heritage railroad. The collection includes eight maps of the line created by the Interstate Commerce Commission in 1918 and two publications concerning the history of both the Wilmington & Western Railroad line and HRCV.