Subseries I.1: Published Articles and Books contains material related to articles and books published by Thomas Whiteside. In general the articles were written for. There are a few outliers, for instance, Whiteside's piece about the 1968 Democratic National Convention, "Corridor of Mirrors" was published in the. Whiteside contributed tofor over 45 years, a majority of the articles he wrote for the magazine are represented in this subseries. He wrote 11 books, and those too are represented, if however briefly, in this subseries. The files consist of research files, made up of articles, audiocassettes, clippings, notebooks, and typed notes. Also present around each article are related correspondence, drafts, galleys and proofs, and typescripts. The correspondence is, for the most part, letters that Whiteside received in congratulations of publication of his book or article. A few contributors of note include, Andy Rooney and John Kenneth Galbraith. There is also correspondence with Whiteside and his publishers and literary agents, Yale University Press, Wesleyan University Press, among others. Some letters to and from Allen Dulles pertaining to a book blurb for Wennerstrom can be found in the correspondence file for "An Agent in Place."

Subseries I.2: Unpublished Articles contains materials related to articles that Whiteside never published. There are three main topics covered in this subseries: French Caves, Joe Camel, and material about the Crytherian Phase. There is also a piece that Whiteside wrote on the arrival of the Beatles to the United States. Like subseries 1, this subseries consists of research articles and clippings, correspondence, drafts, and typescripts.

Series I.3: General Research Files contains research materials not associated directly to an article or book. There are several files related to a Dioxin Study Project that Whiteside took part in during the early 1980s as well as material on George Blake.