This collection is composed primarily of correspondence, memoranda, course material, photographs, drawings and slides. Much of the material pertains to Herdeg's career as a professor at Cornell University's College of Architecture, Art and Planning as well as his career as a professor and subsequent department head at Columbia University's Graduate School of Architecture Planning and Preservation (GSAPP). Many of the photographs are proofs used in Herdeg's Formal Structure in Indian Architecture and Formal Structure in Islamic Architecture of Iran and Turkistan. The basis for the series and subseries order was developed from Herdeg's own groupings. For the majority of the collection, Herdeg's folder titles have been maintained and the material has been arranged chronologically.