The Pig War border confrontation began when Lyman Cutlar shot a British-owned pig on San Juan Island.
The archipelago of which San Juan Island is part lies between Washington State on the United States mainland and Vancouver, in what was then British North America. The 1846 Oregon Treaty had established a boundary along the 49th parallel along ‘the middle of the channel which separates the continent from Vancouver’s Island’. The problem was that San Juan Island itself lies in the middle of the channel, leading both countries to claim sovereignty over it.
By 1859 the British Hudson’s Bay Company had established a sheep ranch on the island. A small number of American settlers had also arrived under the terms of the Donation Land Claim Act, even though the ownership of the land was disputed.
On 15 June 1859 a free-roaming black pig owned by the Hudson Bay employee Charles Griffin began rooting through American settler Lyman Cutlar’s potato patch. Cutlar shot the pig. Although the exact details of what happened next are unclear, a number of sources claim that Cutlar offered $10 compensation while Griffin demanded $100. Whatever the truth, Griffin reported Cutlar to the British authorities who threatened to arrest him. In response the US General William S. Harney sent 66 soldiers from the 9th Infantry, which the British governor responded to by sending three British warships.
By 10 August a force of 461 Americans and five British ships with over 2,000 men were caught in a tense standoff. However, the arrival of British Rear Admiral Robert L. Baynes heralded a de-escalation of tensions after he refused to ‘involve two great nations in a war over a squabble about a pig.’ An international commission eventually ruled in 1872 that America should control the island.