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.