Series I contains correspondence, typescripts with holograph corrections, and galley proofs relating to entries in, and the production of, IESS. Series II includes correspondence relating to changes in articles, production schedules and procedures, and financial records. The Classified Office Files contain correspondence of administrative officers of IESS; memoranda, minutes and agendas of Editorial Advisory Board meetigs; lists of biographers and suggested contributors; and monthly reports. General Production Files are composed of correspondence, invoices, drafts of table of contents, a style manual, editing procedures, and an index. There is also correspondence with prospective members of the Editorial Advisory Board.