August 14, 1779–August 7, 1780 | Journal Daniel Smith's Journal (1779-1780) In 1779, with other surveyors and adventurers from Virginia and North Carolina, Daniel Smith and Thomas Walker set out to extend the Virginia-North Carolina boundary line far beyond the Cumberland Gap. From August 1779 until August 1780, the men traveled from southern Virginia, to the Falls of the Ohio River, and back to Virginia. In addition to their survey duties, the men worked secretly for Thomas Jefferson, meeting with George Rogers Clark at the Falls of the Ohio River to scout locations for the planned Fort Jefferson.
January 24, 1780 | Letter Thomas Jefferson to Joseph Martin, January 24, 1780 Thomas Jefferson instructs Joseph Martin, agent to the Cherokee, to purchase or trade for land for Fort Jefferson, currently being plotted by George Rogers Clark.
January 29, 1780 | Letter Thomas Jefferson to George Rogers Clark, January 29, 1780 Thomas Jefferson issues instructions for the construction of a fort on the Falls of the Ohio, offering the services of surveyors Thomas Walker and Daniel Smith, who are in the field plotting a line between North Carolina and Virginia. Addressing the need to defend the western frontier from British advances, Jefferson authorizes Clark's recruitment of a battalion of soldiers, with land warrants issued as payment. Jefferson also expresses concern over the establishment of peaceful relations with French settlers and Native groups already in the region.
March 1, 1784 | Statute Virginia's delegates cede western counties to the nation. The wrangling between Virginia, Maryland, and other "landed" states and the Congress over the use and distribution of western territory was a long and contentious process. With this document, Virginia's delegates cede land northwest of the Ohio River to the nation.
July 13, 1787 | Letter Northwest Ordinance, July 13 1787. Setting the stage for western expansion, the Northwest Ordinance of 1787 shaped the development of the territory north and west of the Ohio River.
March 18, 1792 | Report Thomas Jefferson to George Washington, March 18, 1792 A detailed examination of the current and future prospect for western expansion and the legal and political ramifications of such movement.
January 23, 1793 | Letter Thomas Jefferson to Andre Michaux, January 23, 1793 Thomas Jefferson's instructions for Andre Michaux's proposed western expedition.
March 10, 1793 | Report Thomas Jefferson to George Washington, March 10, 1793 In his official capacity as Secretary of State, Thomas Jefferson writes to George Washington, reiterating the boundaries of the western frontiers of the United States, particularly as they apply to treaties with Native groups.
April 3, 1803 | Letter Meriwether Lewis to Thomas Jefferson, April 3, 1803 Meriwether Lewis writes to Jefferson regarding his preparations, including his many communications with men of science. Lewis includes his plans for a collapsible boat.
June 20, 1803 | Letter Thomas Jefferson to Meriwether Lewis, June 20, 1803 Thomas Jefferson issues detailed instructions to Meriwether Lewis, addressing every aspect of the upcoming expedition.
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.