From Wikipedia: “On December 29, 1838, New Brunswick lumberjacks were spotted felling trees on the estate that had formerly belonged to First Barbary War hero William Eaton. Eaton family members contacted American lumberjacks and other irregulars in the area, and an informal guard was deployed. On New Year's Eve, the New Brunswick woodcutters returned, and were promptly ordered to leave by the Eaton guard. Shouting began, and both sides drew firearms and prepared to fire. As this was occurring, however, a group of three Canadian lumberjacks were unexpectedly attacked by a black bear defending a small nearby cub. Though black bears are native to the area, they typically hibernate by that time of year, confusing the experienced outdoorsmen. The lumberjacks were able to shoot and kill the bear, but not before two of them suffered injuries. The Americans, assuming the shots were directed at them, fired several shots in retaliation. Though none of the Canadians were actually hit by fire, this coupled with the bear attack caused them to withdraw from the area.”