This treaty transferred the entire Willamette Valley to the United States, displacing indigenous peoples who had inhabited the region for over 10,000 years.
Key Facts
- Date Signed
- January 22, 1855
- Date Ratified
- March 3, 1855
- Date Proclaimed
- April 10, 1855
- Region Ceded
- Entirety of the Willamette Valley
- Prior Indigenous Habitation
- Over 10,000 years
- Location Signed
- Dayton, Oregon Territory
By the Numbers
Location
Cause → Event → Consequence
American settler expansion into the Oregon Territory created persistent conflict and violence against indigenous peoples of the Willamette Valley, including the Kalapuya, Molala, and Clackamas tribes. The United States sought to legally acquire indigenous lands to facilitate settlement and assert federal authority over the region.
On January 22, 1855, representatives of the United States and multiple tribal bands — including the Kalapuya, Molala, and Clackamas — signed the Treaty of Dayton in Dayton, Oregon. The tribes were compelled to cede their lands in exchange for promises of a permanent reservation, annuities, supplies, educational and vocational services, health care, and protection from settler violence.
The treaty transferred the entirety of the Willamette Valley to the United States and resulted in the forced removal of indigenous groups from lands they had occupied for more than 10,000 years. The promised protections and services were frequently insufficient, and the treaty established terms that fundamentally restructured the political and territorial status of the signatory tribes.
Political Outcome
Tribal cession of the Willamette Valley to the United States in exchange for reservation rights, annuities, and promised services
Indigenous tribes held territorial control over the Willamette Valley in the Oregon Territory
United States assumed full territorial control; tribes confined to a promised permanent reservation