The Regional Offices series documents the work and administration of the ACLU's three regional offices: Mountain States Regional Office, concerned with civil rights in the west and Native American rights, the Southern Regional Office, focusing on civil rights in the south, and the Washington, D.C. office, which concentrates on national legislation and the actions of the federal government. The files include correspondence, case files, office publications, research files, and the papers of individual 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 ACLU is the preeminent civil liberties organization in the United States. These records document the work of their national office in the areas of civil rights, children and women's rights, freedom of speech (and all First Amendment questions), and due process, among many others, predominantly from 1970 to 2000.

This collection consists of the papers received and generated by the staff of the Washington, D.C. Office of the American Civil Liberties Union (ACLU) during the 1950s and 1960s. The ACLU is a leading defender of civil liberties in the United States. Founded in 1920, it has been the recipient of sharp criticism for its willingness to defend unpopular causes and has participated in a majority of the landmark cases to come before the Supreme Court in the twentieth century. The Washington Office's primary responsibility is to monitor legislative issues. In the 1950s the office worked against abuses caused by McCarthyism, including loyalty oath requirements, powers of legislative investigating committees, and censorship of free speech and expression. In the late 1950s and early 1960s, the office focused on civil rights issues and the defense of alternative means of self expression. The Washington Office was also deeply involved with defending the civil liberties of those associated with the federal government and its agencies.

Consists of drafts of, and material related to, American author Paul Blanshard's American Freedom and Catholic Power (1949)

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.

Ananda K. Coomaraswamy was a noted art historian and champion of Ceylonese and Indian culture. This collection covers a broad spectrum of Ananda K. Coomaraswamy's work in the fields of art history, philosophy, religion, and social criticism.

Consists of the correspondence of Russian poet, translator, and writer Anatoly Naiman (1936-2022) along with some writings, photographs, personal documents, and clippings. Other individuals represented in the collection include Anna Ahkamatova, Joseph Brodsky, Sergei Dovlatov, Lidia Chukovskaya, Evgenii Rein, and Dmitrii Bobyshev.

The Papers of Andrew C. Imbrie, Class of 1895, (1875-1965) provide information on his undergraduate years, his service as an alumni trustee from 1907 until 1912 (including a period as Financial Secretary of the Princeton University Board of Trustees (1909-1912) during which he had charge of reorganization of the business management of the University leading to the creation of what became the Office of the Controller) and his family's genealogy.

Consists of an open collection of photographs by Angelos Prokopiou.

Consists of miscellaneous papers of George M. L. La Branche relating to angling.