The fonds documents John Mappin’s occupation as an independent antiquarian book seller, his personal interest in the history of print and Canadian politics, and his personal achievements as an author. The wide variety of subject files found in this collection are almost entirely North American based and span from 1733-2004. These records reflect Mappin’s particular focus on Canadian authors and Canadiana in general.

These McGill papers are entirely concerned with his property and estate. They comprise legal documents and copies of letters (some in McGill's hand) concerning his land holdings on St. Paul St., Montréal, in Stanbridge, and in Detroit. McGill's cash book, 1809-1815, and copy by W.D. Lighthall of a deed of conveyance to McGill of some land formerly occupied by the city fortifications, 1805, are also included, as is a blue-print and sketch by W.D. Lighthall of the site of McGill's St. Paul St. house. Estate papers comprise a probate of McGill's will, copied by Alice Lighthall, and his executor's cash book.

McDonald's correspondence, 1791-1860, mostly concerns business and property matters, but also includes personal correspondence. There are statements of account with McTavish, Frobisher & Co., 1799; with McTavish, Fraser & Co., 1803-1804; with McTavish, McGillivray & Co., 1808-1809. There are two volumes of autobiographical notes assembled in 1859 and covering the period 1791-1816.

There is a second copy of the autobiography, probably transcribed in the late 19th century. Written on the front fly leaf is the name: A.E. MacDonald. It has 63 leaves, and there are minor textual variants.

Typed copies of the official and private correspondence, 1814-1821, held in the McCord Museum in the William MacKay Papers. They consist mainly consist of military records such as commissions, 1813-1814, correspondence between members of the British Indian Department, including Lt. Col. Robert McDouall and his description of the siege of Prairie du Chien, with reference to the Omaeqnomenew (Menominee), Hocak (Winnebago), and Meskwaki (Fox) warriors who fought alongside British forces, as well as to the Potawatomi leader Main Poc (referred to as Marpock), 1814-1815 and copies of correspondence of Capt. Thomas Anderson with Lt Col. Robert McDouall on military actions, supplies and Indian relations, 1814-1815. There is also a newspaper clipping about Alexander MacKay and the partnership agreement admitting William MacKay and David Mackenzie into the North West Company in 1796.

Consists of letter from Lord Selkirk to Captain Benjamin Walker dated 14 June 1816 concerning the sale of Selkirk’s land at Salmon River, New York, and his impending departure for the Red River.

There are three letters from Lord Selkirk, one from Lord Dalhousie, and eight from Lady Selkirk. The early letters concern the Red River Settlement and the North West Company. The letter from Lord Dalhousie, 1824, concerns legal matters, and the two late letters, 1828 and 1833, from Lady Selkirk are personal in nature.

The fonds reflects the scientific and literary outreach activities of the Montreal Natural History Society over the course of its existence and contains correspondence, minutes, financial records, council and committee reports, membership lists, donation lists, catalogues of holdings, newspaper clippings, lecture advertisements and weather maps. In addition, the fonds includes reference material to other societies and information regarding the publication and creation of the Canadian Naturalist and Quarterly Journal of Science, Canadian Naturalist and Geologist and the Canadian Record of Science.

The fonds is composed of the following series: 1) Accounting Records (1860-1917); 2) Administrative Records (1833-1887); 3) Catalogues (ca.1829-ca.1925); 4) Correspondence (1871-1896 with gaps); 5) Essays and Lectures (1829-1852); 6) Minutes (1827-1832,1844-1923); 7) Montreal Microscopical Society (1884-1906); 8) Reports (1828-1881 with gaps); 9) Weather Maps (1895-1897).

Fonds consists of six autograph signed letters written at Montreal by Ann Adams, dated between 24 March 1834 to 26 December 1937, to her son Edward H. in Providence, Rhode Island, and Philadelphia. Letters contain local news (churches and organs built, the railroad to St. Johns, fires, printing and publishing, cholera, etc.), observations on the worsening tensions between Papineau and the "Canadiens" and the "Loyalists," and accounts of preaching by an Indigenous convert to Christianity.

Fonds consists primarily of correspondence between Hertel de Rouville and members of the Canadian government, including Chief Secretary of Lower Canada Sir Thomas William Clinton Murdoch (1809-1891) and Governors General Lord Gosford and Charles Bagot, regarding financial losses he incurred during the rebellions of 1837, 1838, and 1839, and half-pay claims dating from his time as captain of the Canadian Voltigeurs during the War of 1812. Also included are five envelopes with wax seals intact.

Collection consists of 38 letters written primarily by John Wood Senior to family members in England. Many of these were written to a sister or sister-in-law and a few are addressed to his brother, Will Wood, a watchmaker and jeweller in London, including two in which Wood includes a list of trade supplies to order. Four letters are from John Wood's son, Peter Wentworth Wood. One letter is by John's wife, Anna. Contents include topics such as the country's economy, Canadian-British politics, the Woods' watchmaking and jewellery business, crops, slavery, and the American Civil War, as well as local Montreal news on subjects such as fires, the Victoria Bridge, a cholera outbreak, the 1856 Railroad Celebration, and a visit by the Prince of Wales. Letters also include family news, particularly of John Wood's children Peter, John, and Charles, seafaring disasters, gold mines, improvements in shipping in the St. Lawrence seaway and the Atlantic Ocean, the expansion of railroads, and the Atlantic Telegraph. Letters date between 25 November 1839 and 13 December 1867. One is a crossed letter.