The Delafields were avid collectors of family history and family-related memorabilia in the Hudson River Valley region of New York state. This collection consists of the papers of the Delafield family and related families, most prominently the Livingstons, containing both personal papers and papers collected for their genealogical and historical significance.

Jacob Viner (1892-1970) is considered one of the greatest economists of the twentieth century. His career was spent at the University of Chicago and Princeton University, and he also frequently served as an advisor to the United States government. His primary academic interests included international economics, international economic relations, and the history of economic thought, but his investigations ranged across many disciplines. Viner's papers document his scholarship, as well as his government service, and include correspondence, manuscripts, reports, and research materials.

The Historical Subject Files Collection documents Princeton University history and related topics from 1746 to the present. The collection consists of documents in almost every two-dimensional format: articles, books and booklets, clippings, correspondence, memoranda, non-photographic images, notes, pamphlets, posters, and reports.

John Foster Dulles (1888-1959), the fifty-third Secretary of State of the United States for President Dwight D. Eisenhower, had a long and distinguished public career with significant impact upon the formulation of United States foreign policies. He was especially involved with efforts to establish world peace after World War I, the role of the United States in world governance, and Cold War relations between the United States and the Soviet Union. The Dulles papers document his entire public career and his influence on the formation of United States foreign policy, especially for the period when he was Secretary of State, and include his correspondence files, as well as his writings, reports, and memorabilia.

The Harold Nicolson Papers consists of papers of the English diplomat, journalist, and biographer Harold Nicolson (1886-1968). These papers primarily contain correspondence received by Nicolson, but there is also a large series of letters written by Nicolson to Richard Rumbold, as well as a few to others. Also included in the collection are manuscripts and/or working notes for four of Nicolson's published works. Furthermore, there is a small amount of papers of others, chiefly correspondence by and to Nicolson's wife, "Vita" (Victoria) Sackville-West.

Consists of a closed collection of more than 5,000 Western Americana photographs, consisting mostly of documentary photographs of the Trans-Mississippi West from the late 1860s to early 1900s, largely from the perspective of white photographers and settlers. Subjects include American Indians (especially studio portraits), natural wonders, cities, towns, buildings, and economic activities (mining, railroads, logging, and agriculture). Some photographs relate to the Indigenous populations of Mexico and Central America. The dimensions, physical formats, and photographic processes of the photographs vary widely.

Consists of the papers of Hungarian-born, Nobel Prize-winning physicist Eugene Wigner, and includes correspondence, subject files, writings, and offprints reflecting his long career in physics.

Bruce and Beatrice Blackmar Gould were co-editors at the Ladies' Home Journal in the mid 20th century. Bruce Gould also worked with the Saturday Evening Post. Their correspondence includes letters between Bruce and Beatrice about their co-editorship and co-authorship, letters with writers for the Ladies' Home Journal, and letters from actresses about the Ladies' Home Journal. Also included is a collection of letters about Marion Crawford's book The Little Princesses, some of Beatrice's speeches, speeches by others, and printed matter.

Charles W. Yost (1907-1981) led a varied career as a diplomat, United Nations representative, writer, and scholar. He was a member of the foreign service intermittently between 1930 and 1971, after which time he devoted himself full-time to writing and teaching. Yost's papers document his professional life in the Foreign Service, as well as his time in academia, and include his correspondence, writings, and photographs.

The organization that became Americans United for Separation of Church and State was founded in 1947 to protect church-state separation and religious freedom, as well as to educate lawmakers, religious leaders, and the general public regarding Constitutional religious liberties. The records document the administration and issues of the organization from its founding and include correspondence, meeting materials, and publications.