Throughout history, people followed riverbanks in search of resources that supported commerce, and rivers enabled the exploration and mapping of North America as major waterways served as trade routes for native peoples, corridors for European explorers and traders, and avenues for American expeditions. In 1810, Robert Stuart, an agent of John Jacob Astor's Pacific Fur Company, traveled by sea from New York to Astoria near the mouth of the Columbia River, and in the fall of 1812 company agents directed him to return to New York and report on their progress. Traveling overland along river courses, his party reached St. Louis in April 1813, and Stuart kept a journal of their route, wildlife encounters, and the landscape because he understood the journey's importance. Following advice from a Shoshone Indian, Stuart and his men likely crossed the continental divide and thus the Rocky Mountains by what later became known as South Pass. Stuart presented his journal to President Madison, and Astor informed Thomas Jefferson of the party's route. Although Astoria was surrendered to the Canadians' North West Company during Stuart's absence, its value to the United States was evident because, as historian Bernard DeVoto wrote in The Course of Empire, it placed the Columbia River country and the vast area later called Oregon in the domain of international relations. Stuart's account and the exploration that followed promoted westward migration, as wider knowledge of the route encouraged emigrants to lay claim to Oregon. Robert Stuart and his eastbound party of skilled trappers camped for five weeks in November and December 1812 on the opposite side of the North Platte River about one mile downstream from this site, built a log shelter near the river, and then moved downstream to winter at present-day Torrington, Wyoming, after a war party of twenty-three Arapohays examined the cabin, assessed his group, and continued north.