The Subject Files Series provides insight into the author's varied interests, including her family history, prominent literary and political figures, her adopted hometown of West Newbury, and the various writers' conferences at which she studied and taught.

Coit's notes on Calhoun are included here as they do not seem to pertain to any one particular book or article. Materials pertaining to Coit's friends include clippings about them and writings by them. The file on John F. Kennedy includes a transcript of Coit's oral history interview about Kennedy and an article by Coit entitled "Miracle of Massachusetts." The Writers' Conferences folder includes notes and brochures.