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.

The American Civil Liberties Union Records, The Roger Baldwin years, document the activities of the ACLU from 1917 through 1950. The files contain materials on conscientious objection, freedom of speech, academic freedom, censorship, and labor concerns. The files reflect work on litigation, advocacy, and public policy. Materials include correspondence and newspaper clippings. Subgroup 1 has been digitized in its entirety and is 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.

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. Subgroup 3, Subseries 5B (Southern Regional Office) has been digitized and is 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.

The Legal Case Files series documents the ACLU's involvement in litigation, ranging from files collected on cases for research purposes to records of cases they were significantly involved in. The records include documents filed with the court, correspondence, lawyer's notes, depositions and expert testimony, transcripts of the trials, newspaper clippings, and research materials on the background of the cases and legal precedents.

The Organizational Matters series documents the administration of the ACLU National Office and their interactions with the regional offices, affiliates, outside organizations, and the general public. The records include committee meeting minutes and mailings, staff files, and department records. The majority of the records are the files of Executive Director Ira Glasser and the records of the Legal Department.