Treaty of Walla Walla
Advice to Travelers
Descendants of Petamyo Mox Mox
Three events near mid-century unleashed a flood of American settlement across the Indian country. In 1846, a treaty with Great Britain fixed the northern boundary of the United States at the 49th parallel, securing the Americans’ title to the Columbia River country. Two years later, the discovery of gold in California began a rush that attracted 250,000 people to what had been a distant province of the young Republic of Mexico. At almost the same moment, the Treaty of Guadalupe Hidalgo ended the Mexican-American war, and transferred a massive arc of new territory to the United States. Suddenly, the United States had become a continental power.
Settlers, merchants, and entrepreneurs heading west from St. Louis were now eager to set up American institutions across the Indian country. They assumed that the land was theirs, and that their needs superceded those of the existing Indian communities. By the centennial of the Lewis and Clark expedition in 1904, more than six million new people had moved to the territory first visited by the Corps of Discovery.