The Oregon Treaty, signed June 15, 1846, established the boundary between Great Britain’s Canadian territory and the United States of America, from the Rocky Mountains to the Strait of Juan de Fuca, using the 49th Parallel as the handy marker. However, the treaty was not exactly clear on the territorial status of the San Juan Islands, so exactly 13 years later, to the day, a war erupted … over a shot pig.
An American farmer shot a pig rooting through his garden. The pig belonged to an Irishman. The two did not agree upon compensation, and “the authorities” were called in, with infantry mustering from the south and the Governor of Vancouver Island instructing marines to land on San Juan Island — though the rear admiral in charge refused to comply with the order, on the reasonable grounds that war over a pig was not worth it. Local troops from both sides lined up against each other, but under command to defend themselves only and not shoot first. All that was exchanged in this war were insults. It turned out to be a bloodless war, discounting the pig, so it might qualify as the best war in American history.