The Peter N. Halgren collection includes periodical clippings and photographs Mr. Halgren used for research on railroads and railroad modeling. It is organized by railroad, topic, locomotive type, car type and other subjects selected by Mr. Halgren. Circus trains make up the contents of several binders. Much of the collection includes photocopies of commonly available periodicals as well as photographs collected by Mr. Halgren. Many North American railroads are covered, including the Southern Pacific Railroad.