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.

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

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.

This material documents the estate of Mrs. Charlotte Frobisher and includes a copy of her will and an inventory, 1820.

This material comprises a group of official documents, and correspondence among various partners. The official documents include four articles of agreement for partnership between various Montréal companies, largely with McTavish, Frobisher and Co., 1790-1802, and a memorandum on the effect of exchange differences on the partners' shares (approximately 1826). The partners' correspondence, approximately 1792-1808, contains letters from Simon McTavish, Isaac Todd, and Alexander Mackenzie concerning provisions, business agreements and loans. A letter from William McGillivray to Mr Justice Reid discusses family matters. One financial ledger for the North West Company contains business accounts and records transactions. The bulk of entries are dated from January 1810 to November 1825, with some entries dated 1861.

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 mainly J.E. Buchanan's correspondence, notably his correspondence with Phyllis Buchanan prior to their marriage, newspaper clippings, agendas and administrative paperwork concerning Phyllis Buchanan and her family, with material related for the First World War and children education in the first half of the 20th century.

A collection of documents from the life of Simon McTavish including a letter to his creditors and a series of legal opinions on the estate of Simon and William McGillivray. Documents' informational value is largely financial in nature.