Work began on the Erie Canal in 1817
Our history books may not mention this as a reason for our decision to build a canal around Lake Ontario, but Canada and the US were enemies in the War of 1812, and both countries embarked on canal-building programs shortly after it ended in 1815. Yes, the Canadians knew about the Erie’s commercial success and no-doubt wanted some of that shipping business, but at least one record suggests that something else was also very much on their minds at the time: Learn more (read the second paragraph of the link).
Hostilities on Lake Ontario – Sept 11, 1813
Battle of Lake Erie – 1813