Treaty with the Kalapuya, etc.

In it the tribes were forced to cede land in exchange for promised permanent reservation, annuities, supplies, educational, vocational, health services, and protection from ongoing violence from American settlers.

[1] The treaty effectively gave over the entirety of the Willamette Valley to the United States and removed indigenous groups who had resided in the area for over 10,000 years.

This drove some of the first American settlers to the region, and the development of the Oregon Trail began to bring larger numbers to the area by the early 1840s.

Starting in the late 1700s, American and European explorers and settlers introduced a series of diseases, causing epidemics that decimated the populations of the Santiam, Tualatin, Yamhill, Luckiamute Kalapuyan, and other indigenous peoples who lived in the region.

[3] By the 1850s, the remaining indigenous population had few options when faced with increased harassment and land encroachment from those who believed that the United States should reach to the Pacific Ocean.

The Americans who arrived almost immediately began sending petitions and letters back east requesting the United States government to formally claim the area and protect them from real or perceived threats, both from the indigenous residents they were displacing and the British.