Contains incoming and outgoing correspondence, the bulk of which comes from 1950-1977. No attempt was made to separate the incoming from outgoing correspondence, but letters are arranged chronologically with the exception of several folders arranged by subject matter at the end of this series. Topics include publishing, meeting arrangements for discussion of a variety of topics, financial matters, requests to read articles, and personal matters. Many of the letters concern issues related to McNickle's tenure at AID as well as his attempts to get his books published. Prominent correspondents include various members and donors to AID, many publishing houses, and Viola G. Pfrommer. Other folders of correspondence have been placed alongside relevant materials in other series.