The archive is divided into two sections, covering the Bennington, Vermont, office and the Cambridge, UK, office. There may therefore be some duplication. Most aspects of the DCP's activities are covered, including appeals for funding, the search for letters, editorial policy, early computerisation, reports, publicity, outreach, and correspondence.

Letters and papers relating to Smith's work on Charles Darwin and the establishment of the Darwin Letters Project: correspondence with Frederick Burkhardt, joint editor, and others; correspondence with Nora Barlow and Robin Darwin about Darwin Papers; and lectures, including the Sandars Lectures, 1967, and Wilkins Lecture, 1982.