Dowling & Kennedy were railroad contractors. The partnership of Dowling & Kennedy and its predecessor, Reynolds, Dowling & Company, were typical of the many small firms that subcontracted to grade sections of railroad rights of way for large general contractors. This collection contains account books, vouchers, and statements covering the receipt of monies from the general contractor and its expenditure for labor and supplies. There are also timebooks, payrolls, and correspondence.

The Mount Carbon Railroad Company was incorporated in Pennsylvania on April 20, 1829, for the purpose of building a railroad from the Schuylkill Canal at Mount Carbon up Norwegian Creek to the forks and thence to Wadesville on the East Branch and Mount Laffee on the West Branch. The collection consist of thirteen laborers receipts issued for the construction of the railroad in 1829 and 1830 by William R. Hopkins, superintendent.

The Phoenix Iron Company began in the late eighteenth century as a manufacturer of cut nails. It later became a major producer of railroad rails and iron and steel structural members. This small collection of records includes incoming correspondence chiefly relating to orders for and deliveries of iron for railroads.

The Phoenix Steel Company began in the late eighteenth century as a manufacturer of cut nails. It later became a major producer of railroad rails and iron and steel structural members. Their records include minutes (1856-1929); stock ledgers; brief of title papers and property maps; legal and financial correspondence and tax papers; account books; and a works diary.

There are many photographs related to the products made at Steelton, Pennsylvania, where the frog and switch division and a rail mill plant were located. There are also plant views. An inspection report of track material furnished by the Pennsylvania Steel Company for Lake Shore & Michigan Southern Railway is included in this part of the collection. Also of interest are views of the Pennsylvania Steel Co. exhibits at trade conventions in Chicago and Atlantic City, New Jersey Some other miscellaneous views are also found with the Steelton material: the Queensborough Bridge in Manhattan; Broad Street Station, Philadelphia; train station in Pittsburgh; Union Station, Washington.

Cambria Iron Works which was established in 1852 officially became the Cambria Steel Company in 1898. That company was acquired by Midvale Steel and Ordnance Company in 1916. Midvale was absorbed by Bethlehem Steel Corporation in 1923.

Approximately 968 glass plates and forty-six lantern slides. There are glass plate negatives with patterns for frogs, rails, and switches. There are no corresponding prints. Some plates contain unidentified images and images of unidentified products. Lantern slides of unidentified products.

The Taylor-Wharton Iron & Steel Company produced frogs, switches and other railroad fittings including couplings, axles and wheels, as well as war material during both World Wars. The company was incorporated in 1912 as successor to the Taylor Iron & Steel Company. The collection contains photographs primarily of products such as dredging equipment, railroad tracks, rollers, crushers, and buckets. The films document dredge buckets in operation and were shot in the United States and at international locations. The collection has been organized into four series: Company history, Plant views, Products, and Films. Each series is arranged alphabetically.