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.

The Printed and Audiovisual Materials series contains the published works of the ACLU, including publications, audio recordings, and videos. These include educational materials published by the ACLU, newsletters, press releases, and public appearances and interviews with ACLU staff.

The Project Files series contains the records of twelve of the ACLU's projects, which each addressed an area of civil liberties violations. Project records typically consist of case files, research files, and project publicity and correspondence. The best documented projects are the Children's Rights Project and Women's Rights Project, and to a lesser extent the Arts Censorship Project, Capital Punishment Project, and Reproductive Freedom Project.

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 an open collection of photographs by Prokopiou.