The Khuzestan Development Project (Iran) series contains the records pertaining to D's development work in the Khuzestan Region of Iran from 1956 to 1979, as well as a small number of projects that extended into the rest of the country. The records predominately document D's construction of the Dez Dam and related work with irrigation and agriculture, and also include correspondence files and other records pertaining to the management of the region's development. Please see the subseries descriptions in the contents list for additional information about individual subseries.

Series 7: Publications About or Relating to David E. Lilienthal includes magazine or professional journal articles about Lilienthal, the organizations he worked for, or subject matter related to his professional career (e.g., atomic energy).

This series consists of miscellaneous papers, ranging in date from the late-13th to the mid-20th century, amassed primarily by John Ross Delafield reflecting his interest in history, particularly his interest in collecting family history family-related memorabilia. Similar to a subject file, the series includes papers created by as well as research and genealogical materials about families related to the Delafields and various other persons (particularly political figures) as well as miscellaneous materials documenting various places and subjects. There are as little as one item or up to several folders associated with each name and topic represented; and while a good number of items are original, a significant amount are copies of original documents. Found throughout this series is the correspondence of John Ross Delafield relating to his research and collecting efforts.

Diverse notes and memoranda slips, including reading notes, library request slips, bibliographic excerpts and memoranda, and memoranda books. Extensive notes on history, philosophy and theology, especially the works of Gottfried Wilhelm von Leibniz (primary and secondary sources). Largely in Gabelsberger shorthand.