The "Pig War" was an example of a small incident that grew to an international confrontation. The Oregon Treaty of 1846 established the boundary between Canada and the United States from the Rocky Mountains westward to the coast. Unfortunately, the provision extending the boundary line through the offshore Gulf Islands was poorly worded. The document stipulated that the boundary in this area was to run down the middle of the channel separating Vancouver Island from the mainland. In truth, several channels existed, including two major ones, Haro Strait and Rosario Strait. This distinction mattered because it would determine ownership of the prized San Juan Island.
During the 1840s and 1850s, the Hudson’s Bay Company established a number of facilities on the disputed island. American settlers established homes and farms there and the Washington territorial legislature made a formal claim to the area in 1853.
This tense, but manageable, situation spun out of control in June 1859 when a pig owned by the Hudson’s Bay Company wandered into an American farmer’s garden and began to feast on the array of vegetables. The farmer defended his property by shooting the pig. HBC officials were outraged and sought the farmer`s arrest. American citizens on the island sent a plea to the mainland for military assistance. In July, George E. Pickett (later of Pickett’s Charge fame) was dispatched to San Juan with a small contingent of soldiers. The British reacted by sending three warships into the harbor to encourage Pickett to withdraw. The American force remained in place and on two occasions was supplemented with additional soldiers. The British countered by sending two more warships.
When President Buchanan learned of these developments, he was displeased. General Winfield Scott was sent to salvage the situation and quickly managed to arrange a mutual reduction in military presence. Later, an agreement for the island`s joint military occupation was reached. The United States soon became embroiled in its civil war and neglected for a number of years to push for the dispute`s permanent solution.
In 1871, the Pig War issue was referred to an arbitration panel under the auspices of Kaiser Wilhelm I. A ruling was handed down the following year, which established the boundary through Haro Strait and made San Juan Island a possession of the United States.