Materials regarding the founding, operations, and activities of The Fortnightly of Chicago and its members. Administrative records include committee records, reports, meeting minutes, gift records, and correspondence. The history and activities of the Society are documented through yearbooks, clippings, photographs, scrapbooks, audiovisual materials, event calendars, guest books, biographical information, and member and guest papers. Also includes the papers of Fortnightly founder Kate Newell Doggett, along with extensive information regarding the history, contents of and maintenance of the Bryan Lathrop House.

Related materials can be found throughout the collection. Oversize materials are described separately at the end of the collection. Meeting minutes are restricted for a period ending fifty (50) years from the date of the meeting described in the minutes.