Treaty of Mount Dexter

The 4,142,720-acre (16,765.0 km2) area ceded was from the Natchez District to the Tombigbee Alabama River watershed, mostly in present-day Mississippi.

The preamble begins with, THOMAS JEFFERSON, President of the United States of America, by James Robertson, of Tennessee, and Silas Dinsmoor, of New Hampshire, agent of the United States to the Chaktaws [Choctaw], commissioners plenipotentiary of the United States, on the one part, and the Mingoes, Chiefs and warriors of the Chaktaw nation of Indians, in council assembled, on the other part, have entered into the following agreement...1.

[1] In February, 1809, a survey was begun to establish the actual boundary lines between the United States and the Choctaw Nation.

The United States contracted with Silas Dinsmoor and Levin Wailes for this survey.

[1] The main signers included James Robertson, Silas Dinsmoor, Pukshunnubbee, Mingo Hoomastubbee, and Pushmataha.