He was born in Upper Canada, the son of Joshua Cornwall, and lived in Camden Township. Cornwall commanded a militia company in 1838. He served as justice of the peace for the Western District. Cornwall died in Chatham, Canada West.
- Johnson, Wilaon (1991),Historical Essays on Upper Canada: New Perspectives ISBN 0-88629-070-8
- Johnson, JK Becoming Prominent: Regional Leadership in Upper Canada, 1791-1841 (1989) ISBN 0-7735-0641-1 pp. 184