The Allison Delarue Collection consists of a draft of Delarue's unpublished autobiography, letters received by Delarue from various friends, associates, and people involved in dance and the theater, and prints, photographs, and objects collected by Delarue relating to ballet and its history.

The Alonzo Church Papers consists of the writings, correspondence, notebooks, notes, and subject files of Alonzo Church (1903-1995, Princeton Class of 1924), the renowned mathematical logician who taught at Princeton University from 1929-1967 and the University of California at Los Angeles from 1967 to 1990, and who was editor of the Journal of Symbolic Logic from 1936 to 1979.

Alpheus T. Mason taught in the Dept. of Politics at Princeton University beginning in 1925 and authored a number of legal works as well as biographies of Supreme Court justices Harlan Fiske Stone and Louis D. Brandeis. This collection consists of papers of Mason, including material relating Stone, Brandeis and Woodrow Wilson.

This collection consists of offprints of articles written by Princeton alumni and faculty; however, in some instances the articles are written about an individual alumni or faculty member. The offprints generally consist of journals, published articles, speeches, lectures, sermons, memorials, and articles from scientific journals and magazines.

The Alumni Association of Nassau Hall, Princeton's first official organization of alumni, was founded on commencement day 1826. The collection consists primarily of administrative materials such as correspondence, meeting minutes, notebooks and reports belonging to both national and regional associations and their committees, most from the first half of the 20th century. Also contains newsletters, alumni directories, scrapbooks, reunion-related ephemera, photographs, and materials documenting reunions and alumni organization activities from the late 19th century forward.

The Alvaro Yunque Correspondence consists of letters, manuscripts of poems, essays and other printed and miscellaneous material by Alvaro Yunque and others.

Consists of correspondence of the American suffragette Alyse Gregory with her friend A. H. Degenhardt.

Consists of approximately 5000 early 20th-century American architectural drawings (blueprint and trace drawings), primarily by C. Grant La Farge and various firms with which he was associated, including Heins & La Farge, La Farge, Clark & Creighton, La Farge, Warren & Clark, La Farge & Morris, and La Farge & Son. There are also groups of drawings by the architects Wilson Eyre, Pennington Satterthwaite (Princeton Class of 1893), Robert Gibson, and a few miscellaneous firms.

The American Ballet Theatre is an American ballet company founded by Oliver Smith and Lucia Chase in 1940. The collection consists of programs of performances of the Ballet Theatre dance company from its first performance in 1940 until 1979.

The American Civil Liberties Union (ACLU) is the pre-eminent civil liberties organization in the United States, utilizing litigation, lobbying, and public education to defend and preserve the individual rights and liberties guaranteed by the U.S. Constitution. These records document the administration and work of the ACLU's national office, regional offices, and legal projects, with particular emphasis on the areas of civil rights, children and women's rights, freedom of speech (and all First Amendment questions), and due process, among many others. The records include case files, correspondence, meeting minutes, research files, and files of staff members. Portions of the records (Subgroup 1; Subgroup 2, Series 2, 3, and 4; Subgroup 3, Subseries 5B) have been digitized and are available for members of the Princeton community to view here. To view the database from outside Princeton University, please see the Guide to the American Civil Liberties Union Records.