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

The collection consists of three manuscripts by Bela Bartok, 1940-1943. These manuscripts totalling approximately 2,170 pages are as follows: 1) Romanian Folk Music - Vol. 1 Instrumental Melodies, Vol. 2 Vocal Melodies, Vol. 3 Texts; 2) Turkish Folk Music; and 3) Serbo-Croatian Table of Materials. Also, a small group of letters by Bartók and other concerning his association with Columbia University.

The correspondence, research, and teaching files of French-American cultural historian and Columbia University professor emeritus Jacques Barzun (1907-2012).

A significant and sizeable archive of primary materials relating to the career of Charles A. Beard, compiled in the 1970s by Miriam (Beard) Vagts and William Beard. The collection includes more than 300 original letters, manuscripts, and printed material.

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

A collection of letters and memorabilia of John William Burgess, his wife, Ruth Payne Jewett Burgess, his son Elisha Payne Jewett Burgess, his daughter-in-law, Annette Curnen Burgess, his grand-daughter, Ruth Payne Jewett Burgess, and the Burgess, Jewett, Payne, and Curnen families. The personal correspondence numbering 17 items, covers the period 1908 to 1927 mainly between John and Elisha Burgess. There are two letters of a social nature from Eleanor Roosevelt and Nicholas Murray Butler and one lengthy post card from George Bernard Shaw to Annette Curnen Burgess. Also, memorabilia including portraits, photographs, books, diplomas, and medals.

Correspondence; manuscripts of books, chapters, addresses, lectures, articles, and other writings; clippings and other printed materials relating to Butler's life and career, and memorabilia, ca. 1900-1947. Also, correspondence, 1891-1946, between Butler and presidents of the United States including William McKinley, Theodore Roosevelt, William Howard Taft, Woodrow Wilson, Warren G. Harding, Calvin Coolidge, Herbert Hoover, Franklin D. Roosevelt, and Harry S. Truman.

Correspondence, manuscripts, notes, clippings, and photographs of or relating to Cardozo, including his lecture notes as a student at Columbia, 1885-1889, and his commonplace books. Also, four boxes of printed and manuscript material collected by George S. Hellman while writing BENJAMIN N. CARDOZO, AMERICAN JUDGE; and photocopies of letters, manuscripts, and notebooks of original Cardozo papers in the Cardozo School of Law Library. Materials re. his estate and will have been added.

Minutes, correspondence, annual reports, press releases, financial records, photographs, memorabilia, audiovisual, digital and printed materials document the philanthropic activities and administration of the Carnegie Corporation of New York. The collection is actively growing, primarily through regular document transfers from the Carnegie Corporation of New York. Andrew Carnegie's biographical information and personal philanthropic activity can be found in Series VII. In addition, his pre-1911 gifts, most notably his donations for libraries and church organs, can be found on microfilm (Series II), in the Home Trust Company Records (VI.A), and Financial Record Books (I.C.1). Grant files (Series III.A), which comprise the bulk of the collection) provide information on projects and institutions founded, endowed or supported by the Corporation. The Special Initiatives series (Series IV) contains the records of task forces, commissions and councils, formed by the Corporation mostly during the 1970s, 1980s, and 1990s to address specific issues. The Corporation's records include those of other Carnegie philanthropic organizations (Series VI), including the Carnegie Foundation for the Advancement of Teaching and the Home Trust Company, both of which shared staff, officers, and office space with the Corporation for a period of time.

Correspondence, minutes of meetings, financial records, publications, notes, subject files, awards, speeches, reports and audiovisual materials document work by the Church Peace Union, its successors Council on Religion in International Affairs and Council on Ethics and International Affairs, and related organizations such as the World Alliance for International Friendship Through the Churches. The first installment of the CCEIA archival materials came to the RBML in 1974, with numerous additions over the years. A major addition in 1982 contained primarily the records of the Board of Directors and their semi-annual meetings, as well as the various programs and institutes of the Council, for the years 1972-1982, along with selected 1930s materials. 1986 addition contains presidential correspondence files, minutes of the Board of Trustees and committees, special projects, programs and conferences files, and the business and editorial files of "Worldview". Correspondents include John Foster Dulles, Jane Addams, Fiorello La Guardia, and Paul Tillich. 1990 and 2000 additions includes files of CCEIA presidents and vice presidents, paper and audiovisual materials on Merrill House Conversation Programs; Educational programs; International Monetary Fund/Lecture series; The Annals Of The Academy Of Political & Social Science; Washington Consultations; Colloquia for the Clergy; Church State Project; Asian Development & The Carribean Initiative; Korea: Year 2000 Project; fundraising files, printed materials and files of the Department of Publications.