[1] His father, James Thomson (or Thompson), was a Scottish Presbyterian from the town of Hawick in Roxburghshire near the Anglo-Scottish border.
He fought at a number of conflicts along the war's Niagara Frontier, including Queenston Heights, Beaver Dams, Chippawa, Lundy's Lane (where he sustained a head wound), and Fort Erie, as well as participating in the capture of Fort Niagara.
When the Cayuga North Township opened for settlement in 1831, Thompson strategically purchased promising sites along the river where mills could be developed.
He eventually owned two sawmills, a gristmill and a carding mill, a cooperage, and a number of stores.
The 10,000 square foot house, built in the Greek revival style,[6][7] was to stay in the possession of the Thompson family until the 1990s.
[9] After Sydenham's death in late 1841, Thompson regularly voted with the Reformers led by Robert Baldwin.