The collection consists of materials documenting Watson's work for PRR, particularly mechanical engineering and rolling stock. Records largely focus on the development of PRR locomotives and passenger cars in the mid-twentieth century.

William McKinley Keller (1901-1974) was a railroad engineer and executive who worked for the Pennsylvania Railroad and the Association of American Railroads. The collection of papers relate to his engineering career working for the two companies as well as a consultant to the railroad industry and some personal correspondence throughout his career.