Series 3, Professional Correspondence, 1907-1961, is the largest series in this collection, and contains correspondence to and from colleagues at Princeton, other educators, political leaders, and Supreme Court justices. Most of this correspondence pertains to constitutional issues facing the nation, his teaching, and his writings. Correspondents include U.S. Presidents from Woodrow Wilson through John F. Kennedy, and noted jurists Hugo Black, Benjamin Cordozo, Felix Frankfurter, John Marshall Harlan, Harlan F. Stone, and Earl Warren.

Series 4, Subject Files, 1910-1958, contains primarily articles and academic papers authored by others on subjects such as the First Amendment, the Fourth Amendment, legislation, liberty, police power, poll tax, the Presidency, and segregation collected by Corwin for his research.

Series 5, Manuscripts and Publications, 1906-1957, contains manuscripts for a few of Corwin's books, including Court Over Constitution and The Doctrine of Judicial Review: Its Legal and Historical Basis and Other Essays. This series also contains publications with articles written by Corwin as well as book reviews and letters to editors.

Series 6, Notes and Class Materials, circa 1930-1951, contains note papers and note cards with class lecture notes and historical information. There are also class exams and syllabi in this series.

Series 7, Photographs, circa 1880- circa 1960, contains black and white photographs of Corwin, including some in his college days, but most taken in mid- to late-life. This series also contains photographs of his wife, children, family members, and friends, though many early photographs are unidentified.

Consists largely of correspondence with Ernst Stein; some other family members and correspondents are represented.