The Alphabetical Correspondence Subseries includes files compiled by Notestein, Ansley J. Coale, and their secretaries. Files are titled by organization and individual names, or subject; those labeled only with a letter (e.g., "A") include correspondence from individuals whose last name begins with that letter or organizational titles beginning with that letter. Some cross-referencing was provided within the files, handwritten on green sheets of paper, presumably by a secretary. The majority of these files contain business correspondence to and from Notestein, with a large percentage being copies of his outgoing correspondence. The correspondence details Notestein's consultation and research work, his critiques of the work of other demographers and scientists, reports and speeches by Notestein and others, as well as the business of the Office of Population Research and the Population Council. Some of the correspondence is also to and from Ansley J. Coale, who took over Notestein's duties at the Office of Population Research after 1959. Notable correspondents include Dr. Irene Taeuber, Frank Lorimer, Frederick Osburn, and Bernard Berelson, all noted leaders in the field of population research. Incoming correspondence included many requests for reviews and commentary, as well as requests for information about fellowship programs and assistance for demographic studies at Princeton.