The collection consists primarily of letters written by Henry Larcom Abbot (1831-1927) to his parents in 1855, journals he kept during his work on the Pacific Railroad Survey in California and Oregon in 1855-1856, and various field notes and celestial observations he took for the survey.

Color lithograph depicting two Navajo riders on horseback. The lithograph was made for the U. S. Pacific Railroad Exploration and Survey Report, 1854.

Gustavus Sohon (1825-1903), a German immigrant, was employed by the U.S. government between 1852 and 1863 as an illustrator and cartographer of explorations of the Rockies and Pacific Northwest. Collection consists of eight tinted lithographs of scenes of the Midwest, primarily Montana, done for the U.S. Pacific Railroad Exploration and Survey Report, 1854-1855.

Collection includes 31 tinted lithographs depicting scenes of the Pacific Northwest done for the U. S. Pacific Railroad Exploration and Survey Report. Scenes include the Columbia River, waterfalls, Nimiipuu (Nez Percé) people, the Palouse River, Hudson's Bay Company, the Cascades, Mount Rainier, lakes, and missions.

Color lithograph of the Cascade Mountains done for the U. S. Pacific Railroad Exploration and Survey Report.

Collection includes five tinted lithographs of scenes of the Pacific Northwest done for the U.S. Pacific Railroad Exploration and Survey Report, 1855. Scenes include a Douglas fir, Mount Hood, Mount Jefferson, and the Three Sisters.