Central Files is composed chiefly of correspondence sent and received between Columbia University administrators and other University officers, faculty, and trustees, as well as correspondence sent and received between University administrators and individuals and organizations from outside the university.

An artificial collection of phonograph records, reels of audio tape recordings, and motion picture films recording a variety of Columbia University academic and extra-curricular activities and events such as lectures; speeches, some at award ceremonies; commencement; installation of Nicholas M. Butler and Dwight D. Eisenhower as presidents of the university; King George VI of England during his visit, 1939; speech of England's Queen Mother, Elizabeth in 1954; homecoming; football, the band; academic and alumni conferences; and radio programs under the auspices of Columbia. Many of the recordings are of Eisenhower. Other prominent personalities include John Foster Dulles, Herbert Hoover, Isidor Rabi, Eleanor Roosevelt, John R. Dunning, and the Shah of Iran.

Professional and personal files including Armstrong's correspondence with professional associations, other engineers, and friends, his research notes, circuit diagrams, lectures, articles, legal papers, and other related materials. Of his many inventions and developments, the most important are: 1) the regenerative or feedback circuit, 1912, the first amplified radio reception, 2) the superheterodyne circuit, 1918, the basis of modern radio and radar, 3) superregeneration, 1922, a very simple, high-power receiver now used in emergency mobile service, and 4) frequency modulation - FM, 1933, static-free radio reception of high fidelity. More than half the files concern his many lawsuits, primarily with Radio Corporation of America, over infringement of the Armstrong patents. Litigation continued until 1967. Other files deal with his work in the Marcellus Hartley Research Laboratory at Columbia University, 1913-1935, and with the American Expeditionary Forces in France during World War I, his Air Force contracts for communications development, Army research during World War II, the Radio Club of America, the Institute of Radio Engineers, FM development at his radio station at Alpine, N.J., the use of FM in television, his involvement in Federal Communications Commission hearings and legislation, and his work with the Zenith Radio Corporation. Also, letters to H.J. Round

Belmont (1878-1979) was an American actress and a prominent public figure. The collection includes correspondence, subject files, and personal materials.

Correspondence, memoranda, manuscripts, documents, photographs and printed materials relating primarily to Coykendall's various involvements with Columbia University, including the Trustees, University Patents, the Columbia University Press, alumni affairs, and the searches for successors to Presidents Butler and Eisenhower. Also, material relating to his membership in the New York State Historical Association. Among the major correspondents are Nicholas Murray Butler, Marcellus Hartley Dodge, Dwight David Eisenhower, Hellmut Lehmann-Haupt, Arthur Hays Sulzberger, Mark Van Doren, and Thomas J. Watson. Also, memorabilia relating to Coykendall's association with the University and the Press.

The materials that comprise the Historical Biographical Files have been collected and added to from a variety of sources over the years by current and previous staff. The files consist of materials related to people who have a connection to the University whether as student, alumni, administrator, faculty, staff, guest lecturer, or honorary degree recipient. Materials generally consist of newspaper and magazine clippings, press releases, programs, ephemera, printed matter, lists, reports, and pamphlets.

The Historical Photo Collection contains images of persons, events, and activities associated with Columbia College (1754-1896) and Columbia University (1896-).

The V. K. Wellington Koo papers document the diplomatic legacy of Wellington Koo as a Chinese statesman and diplomat of the 20th Century. The papers primarily consist of materials collected during Koo's diplomatic career, relating to the Lytton Commission, 1932-1933; the League of Nations, 1931-1940; the United Nations, 1944-1946; his ambassadorships to France, 1932-1941; to Britain, 1941-1946; to the United States, 1946-1956; as the Senior Advisor to the Republic of China from 1956; and as the Judge on the International Court of Justice, 1957-1966. The materials include correspondence, diaries, memoranda, manuscripts, documents, notes, speeches, maps, photographs, printed material, and audio visual material. The bulk of the materials emphasizes China's domestic and foreign affairs, such as the Sino-Japanese conflict, World War II and the Cold War in the Far East region, as well as the League of Nations and the United Nations.