The General Correspondence series contains routine correspondence with Harlan, including invitations to law conferences, lunches, and events, and requests for autographs, biographical information, and statements. Also included are letters regarding Harlan's personal finances, club memberships, travel arrangements, and thank you letters for books and articles that Harlan received.

The Speeches, Statements, Interviews, Etc. series includes the text, as well as drafts and related correspondence, for speeches given by Harlan at universities, law associations, and law conferences, as well as a few interviews, statements, and remarks. In some instances, there is only notes or outlines for the speech, rather than the full text. Subjects covered by Harlan in his speeches include how the Supreme Court works, a wide variety of legal issues, and education.

The Writings series is composed of articles, theses, and other writings by Harlan, about Harlan's career as a United States Supreme Court Justice, and about judicial and legal issues. Please see the subseries descriptions in the contents list for additional information about individual subseries.

The Appointment Records series is composed of Harlan's calendars and other daily appointment books. The calendars contain brief entries with the names of individuals with whom Harlan was meeting and calling during his career as a lawyer and a judge.