The Union Pacific Historical Society was founded September 1, 1984 in Denver, Colorado to collect, organize, distribute, and publish information relating to the operation and equipment of the Union Pacific Railroad. It is an independent non-profit organization that preserves the history of the Union Pacific Railroad from its beginning in 1862 to present time. The Society is not supported by or affiliated with the Union Pacific Railroad other than the preservation of its history. Collection contains Union Pacific publications, newsletters, diagrams and drawings, track charts, timetables, reports, maps, photographs, slides, negatives, and books. The Union Pacific Historical Society digital collection is a small sample of Union Pacific images found in the collection.

The Manufacturers Aircraft Association was a corporation formed in 1917 at the request of the National Advisory Committee for Aeronautics to implement and administer a cross-licensing agreement. It was a clearing house for aircraft patents, and important in the development of the aircraft industry. The records document the history of aircraft and the relationship of the MAA with its members, the military, and congress.

Martin Jensen was a pioneer aviator. He was a barnstormer and stunt pilot, crossing the country in a biplane that he designed. He placed second in the 1927 Dole Trans-Pacific Air Race, a race from Oakland to Honolulu in which ten pilots died. The collection contains correspondence, scrapbooks, photographs, telegrams, and technical reports related to Martin Jensen's career in aviation and as a pioneer aviator.

The Howard F. Greene collection consists of materials related to railroads and railroad history Greene collected throughout his life. A majority of the material is related to railroads in New England and on the East Coast. However, material related to central and western railroads is present as well, as is a small amount of material related to bus and air lines. Records from railroad clubs Greene belonged to are included. The collection includes financial records, artifacts, correspondence, publications, advertisements, maps, blueprints, and prints, among many other materials.

William Wayne Morrison (1898-1977) was passenger agent of the Union Pacific Railroad and a historian of emigrant trails and pioneer graves. Collection contains materials collected by Morrison for his research on emigrant trails and grave sites in the Western United States. Included are transcripts of diaries and narratives of emigrants, photographs of gravesites, research materials, and secondary sources.