This war's only casualty was a pig

In 1859, San Juan Island, between Vancouver Island and the mainland, sat in a limbo: the border treaty between the United States and Britain was so vague that both claimed it. American settlers lived there alongside British employees of the Hudson's Bay Company.

On June 15th, American farmer Lyman Cutlar found a pig rooting through his potato patch. Not for the first time. He shot it. The pig belonged to a British employee, Cutlar refused to pay what was demanded, and the machinery lurched into motion: American soldiers landed, and five British warships carrying over two thousand men ended up anchored opposite them.

Nobody fired. The joint occupation lasted twelve years, until an international arbitrator — Kaiser Wilhelm I — awarded the island to the United States in 1872.

Final death toll of the conflict: one. The pig.