Isaac Todd was born in 1742 in Ulster, Ireland, and died in 1819 in Bath, England. He was the son of John Todd and Elizabeth Patterson. Todd immigrated to Canada and was established in business in Montreal in 1765. He never married but had one daughter named Eleanor Todd with his housekeeper Jane Kyle, who he provided for in his will. In the summer of 1766, Todd was arrested for trading without a license on Lake Ontario. Around that time, he petitioned Governor Murray to reduce restrictions on the fur trade. In 1769, Todd became a member of the grand jury for the District of Montreal and signed a petition in favour of an elective assembly. He had numerous partnerships, with James McGill, Benjamin and Joseph Frobisher, Richard McNeall, and George McBeath. In early 1773, he and James McGill travelled to Michilimackinac with independent fur trader Peter Pond and some of his goods. One year later, Todd became a business agent in Montreal for Phyn, Ellice and Company of Schenectady, New York. That fall, he was appointed, along with McGill, to a committee charged with drawing up a petition to the King and British parliament opposing the Quebec Act while finding means to redress the merchants’ grievances. In 1775, Todd served as a lieutenant in the British militia during the Revolutionary War. In 1781, he and McGill became Montreal agents for the Niagara merchants Robert Hamilton and Richard Cartwright. Todd was a member of the grand jury and was made captain in the British militia in 1787. Throughout the 1790s, his and McGill’s principal commercial pursuits, conducted from warehouses on Rue Saint-Paul, continued to be related to the fur trade. They imported manufactured goods from Britain and tobacco and spirits from the West Indies to sell to other merchants. From 1800 to 1807, Todd joined the Quebec firm of Lester and Morrogh to supply provisions to the British army in Lower Canada. After this, Todd travelled continuously to Niagara, Upper Canada, New York, and England for about six years. He was a founding member of the Beaver Club in Montreal and the Canada Club in London, and he received a commission as justice of the peace for the District of Montreal.