The collection consists primarily of material relating to Morris's role in the construction of the Union Pacific Railroad and the Northern Pacific Railroad. Included are 14 original letters by Morris (1867-1876), most written from the field to his future wife during the Union Pacific Railroad construction; an original carte-de-visite photograph of Morris; a photograph (copy) of General Grenville Dodge and his engineers and staff at Promontory Point (Utah); a photograph (copy) of the juncture of the Central Pacific and Union Pacific trains at Promontory Point; a 3-ring binder of photostatic copies of "Diaries and Letters of Thomas Burnside Morris" (1869-1876); and typed excerpts from the Utah part (1868-1869) of that binder. Morris's original autograph commencement essay (New York University, 1861), 2 letters (1868, 1870) by cousin D. W. Davis to Miss Sallie Sletor (Morris's future wife), a genealogist's report on the career of Morris, a summary genealogy of the Morris family, and a copy of a reference to Morris in Stephen E. Ambrose's Nothing Like It in the World (2000) complete the collection.