He was born in Carbost on the Isle of Skye, Scotland in 1803 to Ronald Stewart and Isabella McLeod. He came to Glengarry County in Upper Canada, shortly after landing in Quebec, with his family of 9 siblings, recently widowed mother, grandmother, and uncle. He moved to Bytown, later Ottawa, in 1827, where he opened a store and tavern. He was elected to the first town council in 1828. He helped found the Carleton General Protestant Hospital, later the Ottawa Civic Hospital, and then the Wallis House.