The Pig War was a confrontation in 1859 between American and British authorities over the boundary between the United States and British North America. The specific area in dispute was the San Juan Islands, which lie between Vancouver Island and the North American mainland. The Pig War, so called because it was triggered by the shooting of a pig, is also called the Pig Episode, the Pig and Potato War, the San Juan Boundary Dispute or the Northwestern Boundary Dispute. The pig was the only "casualty" of the war, making the conflict essentially bloodless.