Horatio Allen (1802-1889) was a noted civil engineer and inventor, who worked with the Delaware & Hudson Canal Company, the South Carolina Canal and Railroad Company, the Croton Aqueduct, and the New York & Erie Railroad. The bulk of his the papers is personal correspondence (1818-1864), and biographical materials collected by his family. Also included is a small collection of Allen's business papers, particularly concerning his work on the New York & Erie Railroad.

Cape Charles was established in 1884 as the southern terminus of the New York, Philadelphia and Norfolk Railroad. The collection consists of photographs showing the early development of Cape Charles. Views of the wharf and harbor areas and the steamship "Cape Charles" built by Harlin and Hollingsworth of Wilmington, Delaware, comprise nearly half the collection.

David Harrison Cope (1913-2001) held a lifelong interest in railroads and, in particular, steam locomotives. He began collecting photographs at an early age. This collection primarily consists of black and white photographs and negatives of steam locomotives from a variety of railroads, but it includes some other rolling stock, station photos, related railroad items such as coaling stations and some street railroads, interurbans, and trolley images.

The Exposicion Internacional del Centenario commemorated the centennial of the May Revolution in Argentina and its consequent independence from Spain. It was an international exhibition that was held in 1910 between May and November in the capital of Buenos Aires. The photographs in the album consist of views of France's exhibit and include the exterior and interior of the pavilion.

This collection consists of glass plate negatives and photographic copy prints which were made directly from the negatives. The images document an array of subjects, though the majority of the images are of locomotives, railroad cars, railroad stations, and other railroad infrastructure. Various landscape and cityscape photographs are also included. Where it is possible to identify the locations, the majority of images document sites in Pennsylvania, though photographs of sites in New York state and Ontario are also present.

Founded in 1846 with headquarters in Philadelphia, the Pennsylvania Railroad Company (PRR) was an American Class-1 Railroad that pervaded early American culture. As a chief source of employment and transportation, the PRR served as a national symbol of America's progress as a leading industrial nation. This item is a poster featuring an E6s Atlantic class locomotive on the turntable at the Pennsylvania Railroad's 46th Street Enginehouse in West Philadelphia. The poster was created to celebrate 150th anniversary of the Pennsylvania Railroad's charter.

The Joseph D. Lovell Locomotive Rosters constitute a partial roster of Pennsylvania Railroad steam, electric and early diesel locomotives to 1946. The collection also contains seven small ledgers listing the production of not only the Juniata Shops, but also the earlier Altoona Machine Shops (1866-1904) and locomotives purchased from outside builders, principally the Baldwin Locomotive Works. His lists include rosters for both the Pennsylvania Railroad proper and its predecessor lines.

There is also a folder containing copies of letters and notes by Robert B. Watson documenting the provenance of the records.

Samuel Vauclain (1856-1940) was an engineer, inventor, and was president of Baldwin Locomotive Works from 1919 to 1929. This collection contains album pages with snapshot photographs recording a month long Canada-U.S. transcontinental railroad voyage taken in July and August 1922 by Mrs. and Mrs. Samuel Vauclain, their daughter, and granddaughter in their private car, "Manhattan."

The Stanton steam-generated power plant began operation at Harding, Pennsylvania in 1927. It was run by the Scranton Electric Company, which was later acquired by the Pennsylvania Power & Light Company. Most of the photographs in this collection are snapshots showing the plant and employees between 1934 and 1936. There are many that show a flood which took place on March 17, 1936. The three newspaper clippings report on the demolition of the plant between 1973 and 1976.

The Baltimore and Ohio Railroad was the first common carrier railroad in the nation began operating in 1827. It spanned as far north as New York and as far west as St. Louis and Chicago. This is a small collection of souvenir postcards that were published for the The Fair of the Iron Horse, Baltimore and Ohio Railroad's centenary exhibition and pageant of 1927. It was held near Baltimore, Maryland.

Thomas Lansford Foster (1894-1956) was manager of export sales for Baldwin Locomotive Works in Eddystone, Pennsylvania. Baldwin Locomotive Works was a manufacturer of railroad locomotives from 1825 until 1972. This small colleciton consistate of five photographs showing Thomas L. Foster with other Baldwin staff and customers visiting the headquarters.

William Liseter Austin (1852-1932) was an executive of the Baldwin Locomotive Works in Philadelphia. Baldwin Locomotive Works was a manufacturer of railroad locomotives from 1825 until 1972. This small collection consists of six pocket notebooks carried by Austin on separate business trips between 1879 and 1892. The trips were undertaken to confer with representatives of Baldwin's customer railroads concerning proposed designs or faulty performance of Baldwin locomotives.

Wilmington is the largest city in Delaware located on the Christiana and Brandywine Rivers. This collection consists of three reproduction photographs of diverse subjects: an A5A steam locomotive #1167 of Reading Railroad crossing the road at Greenville, Delaware; a unoccupied trolley car in Wilmington, Delaware, originally built by the Peoples Railway Company in 1904; a postcard illustration of the Delaware Trust Building, Wilmington, Delaware.