November 29, 1782 | Letter Arthur Campbell to Thomas Jefferson, November 29, 1782 Arthur Campbell writes to Thomas Jefferson about fossil finds in the West and possible a possible western border that may result from negotiations with the British.
January 24, 1784 | Letter Thomas Jefferson to Thomas Hutchins, January 24, 1784 Thomas Jefferson writes to geographer Thomas Hutchins with questions and remarks about one of Hutchins' pamphlets, "A Topographical Description of Virginia, Pennsylvania, Maryland and North Carolina, Comprehending the Rivers Ohio, Kenhawa, Sioto, Cherokee, Wabash, Illinois, Mississippi, &c...With a Plan of the Rapids of the Ohio, A Plan of the Several Villages in the Illinois Country, a Table of the Distances Between Fort Pitt and the Mouth of the Ohio." In his remarks, Jefferson notes several mistakes in the work.
February 11, 1784 | Letter Thomas Hutchins to Thomas Jefferson, February 11, 1784 Thomas Hutchins responds to Thomas Jefferson's January 24, 1784 note questioning calculations made in one of Hutchins' pamphlets, "A Topographical Description of Virginia, Pennsylvania, Maryland and North Carolina, Comprehending the Rivers Ohio, Kenhawa, Sioto, Cherokee, Wabash, Illinois, Mississippi, &c...With a Plan of the Rapids of the Ohio, A Plan of the Several Villages in the Illinois Country, a Table of the Distances Between Fort Pitt and the Mouth of the Ohio."
March 1, 1784 | Report Resolutions from the Committee for the Western Territory, March, 1, 1784. With Jeremiah Townley Chase and David Howell, Thomas Jefferson issues recommendations for the division and government of the western edges of United States territory. The preferred boundaries of future states are laid out and vaguely classical and Indian names are given the various regions. Congress did not adopt the Ordinance as Jefferson submitted it, primarily rejecting the abolition of slavery in the region and Jefferson's nomenclature. As passed by Congress, it became the Ordinance of 1784.
May 21, 1784 | Letter Thomas Jefferson to James Monroe, May 21, 1784 Thomas Jefferson worries about the evolving western borders and territory of the United States.
November 12, 1799 | Letter Daniel Clark to Thomas Jefferson, November 12, 1799 Daniel Clark writes of Philip Nolan's close brush with death in New Mexico and informs Jefferson of Nolan's plan to travel to the United States. Clarks takes the liberty of sending along a box of pecans for Jefferson.
January 18, 1803 | Report Thomas Jefferson to United States Congress, January 18, 1803 Thomas Jefferson's confidential report to Congress planned westward expansion and the United States' relationship with Native Americans.
April 13, 1803 | Letter Albert Gallatin to Thomas Jefferson, April 13, 1803 Albert Gallatin responds to Jefferson's planned instructions to Lewis by stressing the importance of evaluating the suitability of the parts of the trans-Missouri region not included in the Louisiana Purchase. He wonders if British appropriation of the region is a possibility.
November 16, 1803 | Letter Thomas Jefferson to Meriwether Lewis, November 16, 1803 Thomas Jefferson updates Meriwether Lewis on political activity around the event of the Louisiana Purchase. Jefferson includes notes from the explorer Truteau that detail population and activities of some native groups living west of the Mississippi.