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.