The Samuel Greenlee Papers consists of Greenlee's typescripts, printed material, correspondence, photographs and awards. Biographical material in the collection highlights Greenlee's life and published works. The correspondence featured contains many letters written by Greenlee to his close friend, "Smalley," Mike Cook. In the letters, Greenlee discusses his work and travels in Europe. Ephemera in this collection includes magazines, newspapers, and reviews of Greenlee's work. The photographs in this colleelction show Greenlee as an older man surrounded by friends and family.

The first part of the collection consists of letters written by the novelist William Makepeace Thackeray (1811-1863). Also here are manuscript fragments and pen and pencil sketches by Thackeray. The letters are principally from the last fifteen years of his career, after the publication of Vanity Fair, and concern his lecture tours and opinions on literary subjects. A few are rhyming and whimsical social notes.

The Vince Clemente Papers consist of published and unpublished manuscripts, correspondence (including John Ciardi, John Hall Wheelock, and William Heyen) and printed ephemera. Materials date primarily from the 1980s forward, although there is some earlier correspondence. Materials are organized over time as acquired beginning in 2000 and by subsequent updated acquisitions from Vince Clemente.

The Whitney Rogers Cross Papers includes carbon copies of his M.A. thesis, Creating a City: the History of Rochester from 1824 to 1834 (University of Rochester, 1936), and of his Ph. D dissertation, The Burned-Over District, 1825-1850 (Harvard University, 1944).

The collection contains professional correspondence and departmental correspondence from Riker's years at Lawrence University and at the University of Rochester along with papers written by Riker, both published and unpublished, many including rough drafts and correspondence concerning revisions.The collection also contains many papers written by other political scientists who sent copies to Riker for comments. Forty-two books with marginal comments by Riker are included at the end of the collection.