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.

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.

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 letters written to P.M. Roget by various people, 1830-1856.

This collection reflects Henry S. Chapman's relationships with a number of important figures in Montreal's political and business history, between roughly 1833 and 1853, the period following Chapman's return to London. A significant amount of the material in this collection is related to the 1837-1838 Upper and Lower Canada Rebellions (especially in Montreal), as well as events occurring immediately after the uprisings.

Consists of copies of original material, chiefly correspondence, arranged roughly by date. The contents of letters (1835-1853) include business partnerships, political reform, and personal news. Significant correspondents include Louis-Joseph Papineau, Louis-Hippolyte La Fontaine, Jacob Dewitt, François-Antoine Larocque (of Laroque and Bernard), Joseph Perreault, and Edmund Bailey O’Callaghan. There is also a partial manuscript on Canadian history and pages from a scrapbook, both dating from the 1830s.