On September 7, 2007 at 1:30 p.m., the Ontario Heritage Trust unveiled a provincial plaque to commemorate Bethune-Thompson House at the house in Williamstown, Ontario.
Built by Loyalist settler Peter Ferguson in 1784, the original log cabin on this site is one of the oldest surviving buildings in Ontario. The cabin walls were constructed using a French Canadian technique called poteaux sur sole where vertically placed, squared logs were held together by horizontal plates located along the top and bottom. The larger home adjoining it was built in 1804 by Reverend John Bethune (1751-1815), the first Presbyterian minister in Upper Canada. This home also incorporated a French Canadian construction technique, colombage pierroté, which used a timber frame filled with masonry rubble. The fireplace overmantle installed by Bethune is one of few remaining in the province. In 1815 David Thompson (1770-1857) acquired the house and lived here until about 1836. Thompson was an explorer and cartographer who surveyed much of what is now western Canada and mapped out the Canada-United States border. The house presents a unique architectural and historical record of early Ontario.