Multiple sources have reported that Canada and the United States have announced that the Canada–United States border is about to close to non-essential travel in an effort to reduce the spread of Covid-19. For example, see https://www.cnn.com/travel/article/essential-travel-coronavirus/index.html
"Well I think essential is medical, we have military working together, we have industry working together, and again, it's not affecting trade, so things like that," said President Trump. "But just leisurely 'let's go to a restaurant and have dinner,' which a lot of people do ... we have ended on a temporary basis."
When was the last time either Canada or the US banned citizens or residents of the other from visiting for tourism or other non-essential purposes? My guess is the War of 1812, but I can't seem to find the answer online.