Thomas Clark, merchant and officeholder (b probably in Dumfrieshire, Scot c 1770; d at Niagara Falls Oct 1835). Clark arrived in Upper Canada in 1791 and engaged in portaging and merchandizing under the patronage of his cousin, Robert Hamilton. Around 1808 he entered into partnership with Samuel Street to run 2 large-scale milling, processing and manufacturing complexes on the Niagara River. He acted as an agent and adviser to Lord SELKIRK on his settlements at Baldoon and Red River. He expanded into land speculation and large-scale money lending, including to the government.
An early supporter of Robert GOURLAY, he later opposed him. As a legislative councillor, Clark was a powerful opponent of land reforms and a promoter of communication improvements. He was the richest and one of the most important entrepreneurs in Upper Canada at his death.