1808 treaty between the United States and representatives of the Osage people
One of the first major treaties in the Louisiana Purchase territory, the Osage ceded vast Missouri and Arkansas lands, shaping subsequent Indian removal policy.
Key Facts
- Date signed
- November 10, 1808
- Date ratified
- April 28, 1810
- Land ceded
- All Osage land east of Fort Osage in Missouri and Arkansas north of the Arkansas River
- Survey adjustment
- 23 miles westward to the mouth of the Kansas River (1816)
- Context
- One of first two major treaties in newly acquired Louisiana Purchase territory
By the Numbers
Location
Cause → Event → Consequence
Following the United States' acquisition of the Louisiana Purchase, the federal government sought to formalize control over vast new territories. The Osage Nation held extensive lands in present-day Missouri and Arkansas, and U.S. authorities pursued treaties to legally transfer indigenous land titles to facilitate American settlement and governance of the region.
On November 10, 1808, the Treaty of Fort Clark was signed at Fort Osage (then called Fort Clark) between the United States and the Osage Nation. Under the terms, the Osage ceded all their land east of the fort in Missouri and all land in Arkansas north of the Arkansas River to the United States, with ratification following on April 28, 1810.
The Osage, dissatisfied with the treaty's terms, sided with the British during the War of 1812. After that conflict, surveyor John C. Sullivan demarcated the ceded territory in 1816, adjusting the boundary westward to establish the Indian Boundary Line. This boundary later formed a legal and geographic basis for the Indian Removal Act of 1830, which displaced nearly all tribes from east of the line.
Political Outcome
The Osage Nation ceded all land east of Fort Osage in Missouri and Arkansas north of the Arkansas River to the United States; the resulting boundary later underpinned the Indian Removal Act of 1830.
Osage Nation held sovereign territorial control over extensive lands in Missouri and Arkansas
United States acquired legal title to Osage lands east of Fort Osage, establishing the Indian Boundary Line