Jean Baptiste Rousseau was a fur trader, merchant, government official, and officer in the British Indian Department in Upper Canada.
His father, Jean-Bonaventure Rousseau, was a fur trader, operating out of the area around Lake Ontario.
Rousseau had strong ties with Joseph Brant, the influential Mohawk leader who had fought with the British during the American Revolution.
John Graves Simcoe, the first Lieutenant Governor of Upper Canada, granted Rousseau 500 acres around his fur trading post on the eastern bank of the Humber River in what is now the Swansea neighbourhood.
[1][3] He was owner, or part-owner, of multiple grist mills and taverns, in Kingston, York, Ancaster and Brantford.