The P. and A. Filicchi papers are a collection of original letters and transcriptions compiled by William Crowninshield Endicott in the early 1930s when he was conducting research for a book on Joseph Peabody. The collection contains both business and personal correspondence between the Filicchis and the Peabodys. This collection has been divided into three series.

Series I. Business Papers contains original and transcript copies of business letters and transactions between the firm of P. and A. Filicchi and Joseph Peabody. The majority of the original letters were in a number of letter book volumes and the folder names reflect the number of the volume in which they came from. It is unclear where the original letter books are now. At the front of volume one is an explanation of the collection provided by William Crowninshield Endicott. Also included in this collection is a letter book which appears to have been owned by P. and A. Filicchi.

Series II. Personal Papers contains original and transcript copies of personal correspondence between the Filicchi family and the Peabody family. Similar to the business papers, one folder has been identified as originating from a letter book volume.

Series III. Other contains correspondence to William Crowninshield Endicott about the use, transcribing, and purchasing of the Filicchi letters. Transcriptions from volume three include an introduction from Endicott. Also included in this series is genealogical information about the Filicchi family collected by Endicott.