Fonds contain the personal and professional dealings of the Papineau Family, beginning with Louis-Joseph Papineau in 1828, following through his descendents, to 1943. Dealings include land grants, social events, real estate, interpersonal and business related financial notices, notes on construction projects supervised by or funded by the Papineau family, and charitable pursuits.
The fonds consists of the following series: Legal, Business, and Financial Documents, Ledgers, Account Books, and Notes, Correspondence & Personal Papers, Genealogical Materials. Majority of the files are titled according to creator rather than content and series are contained within chronological boxes (with the exception of container number 9 belonging to the Legal, Business, and Financial Documents series alongside container number 1 and container number 2).
These materials were created for the purpose of keeping track of the interpersonal and business transactions of the Papineau family.

Collection consists of 36 autograph letters written to James Cameron and his son Archie. The correspondence includes letters by friends, associates, and members of the Cameron family in Toronto, Lake Beauport, Scotland, England, Hull, and Montreal. Subjects include family news, freemasonry, business (regarding deed of sales), factory work in Toronto, curling, and an April Fools' Day letter. With three extant envelopes.

The collection consists of ephemera, artifacts, and publications related chiefly to the Expo 67 World Fair in Montreal and some documents relating to its continuation, Man and His World (Terre des Hommes), an exhibition that was the successor to Expo 67. Many of the records and artifacts were produced by participant countries and sponsors or by the Canadian Corporation for the 1967 World Exhibition. Ephemera includes postcards, visitor passports, and ticket stubs, while other textual documents include guidebooks, magazines, catalogues, books, clippings, information manuals, and some unpublished planning documents. Artifacts include license plates, vinyl records, letter opener, bottle caps, shopping bags, and pins. The collection features pamphlets and brochures for numerous pavilions, events, services, and countries featured, as well as many maps for the Expo 67 grounds and documents related to subsequent seasons of Man and His World.

Fonds contains five notebook kept by medical student S. J. Bennett while studying at McGill University's Faculty of Medicine. Each notebook is devoted to a subject of study, including one notebook each labelled "Medicine", "Bacteriology" and "Obstetrics" and two notebooks labelled "Pathology." The notes inside are dated between 1907 and 1908. The notes are organized in some cases by instructor and in some cases according to medical conditions.

The collection consists of 10 ink manuscript maps and plans on paper, some hand-coloured, depicting the earliest settlements and fortifications at Montreal and Quebec City. The earliest dated document is a plan of the fort of Quebec and is dated 1635. The earliest document in the collection depicting Montreal is believed to date back to 1642. The maps and plans were prepared by Jean Bourdon, seigneur and surveyor for the French colony. Included in the collection is a plan of the earliest Fort Richelieu of which nothing had previously been known. There are also detail drawings of riverside fortifications, probably near Montreal.

The fonds consists of manuscripts and drafts of literary compositions and other working documents, as well as professional and personal correspondence.

The fonds contains photographs, drawings, textual records, and other material used by France Gagnon Pratte as the basis for her 1987 book, "Country Houses for Montrealers, 1892 - 1924: The Architecture of E. and W.S. Maxwell". There are also records related to a book project on the architecture associated with the Canadian Pacific Railway Line.