Lewis is asked by President Jefferson to be his secretary-aide
Announcement of Louisiana Purchase.
Expedition begins.
Expedition marks first 4th of July west of the Mississippi by firing the keelboat's cannon, and naming Independence Creek.
Corps of Discovery meet with representatives of the Oto and Missouri Indians, give peace medals, 15 star flags and other gifts.
Near present day Sioux City, Iowa, Sgt. Charles Floyd dies of a probable burst appendix. Captains name hilltops where he is buried Floyd's Bluff and a nearby stream, Floyd's River
Lewis commits suicide at Grinders Stand, an inn south of Nashville
Sacagawea dies at Fort Manuel. Clark, who is St. Louis, assumes custody of Jean Baptiste, as well as her daughter, Lisette.
William Clark dies at the home of his eldest son, Meriwether Lewis Clark. William Clark had married Julia "Judith" Hancock for whom he had named a river while on the expedition.