The Pig War began with a problem specific to the Age of Exploration: A number of different countries had sent men in boats to sail along the western coast of North America and map parts of the interior. Those countries all believed, by virtue of this act, that this large stretch of land now belonged to them. (The people who had been living in these lands before they were “discovered” by European powers were not considered in this political calculus.) In the early 19th century, Britain, the United States, Russia, and Spain all had designs and claims on what was called Oregon Territory, which stretched from what’s now the southernmost border of Alaska, down to California, and east to the Rocky Mountains.