From the primary sources
The Lewis and Clark Expedition was woven into the tapestry of one of the most significant events in the history of the United States of America—the Louisiana Purchase. This timeline details the significant events with excerpts from—and hyperlinks to—the primary sources.
The President’s representatives in Paris had bargained successfully with Napoleon’s bureaucrats not only to buy the port of New Orleans, then the keystone of the continent, but also to acquire, at three cents an acre, an area extending from the Mississippi River to . . . where? No one knew until Meriwether Lewis stood at the crest of the Rocky Mountains at a place known today as Lemhi Pass, on 12 August 1805.
Easter week in Paris, 1803, was truly momentous for the young United States of America. The American Minister to France, Robert R. Livingston was sent to discuss the difficult question of New Orleans, the Mississippi and Franco-American relations.
Analyzing Whelan's invoice
by Gregory J. Higby
Prior to starting, Lewis ordered 29 botanical and chemical medicines plus some related equipment and supplies. The contents of Lewis’s list have much to tell us about the medical challenges he expected to face on his journey.
Lewis's reference book
by John C. Van Horne
What was it about du Pratz’s History of Louisiana that so interested Lewis? The book not only provided geographical information, it was the model that Lewis and Clark were to follow when reporting to President Jefferson.
Mapping the American future
by Joseph A. Mussulman, Pierce Mullen
Determining the extent of the upper Missouri watershed was the single most important task Lewis and Clark faced. Their search for the westernmost source of the Jefferson River nearly cost them their lives.
14,000 years of change
by Pierce Mullen
It begins 14,000 years ago with Indian occupancy of the lower Mississippi Valley. La Salle comes in 1682 claiming it for France.
On 9 April 1682, René La Salle, claimed “possession of this country of Louisiana.” Thus, without any belligerent confrontations began the decline of one already ancient meta-culture, and the rise of a succession of new empires.
The Louisiana Purchase and the lure of its beaver population led to a veritable flood of traders and trappers moving toward the Upper Missouri and the Northern Rocky Mountains and the slow abandonment of the overland trade in the United States by Canadian and British interests.
Louisville, Kentucky
Falls of the Ohio, KY-IN Historic travelers give their impressions of the Louisville and Clarksville area. In Washington City, Thomas Jefferson asks the House of Representatives to ratify the Louisiana Purchase treaty.
Louisville shipyards
Falls of the Ohio, KY-IN Two new recruits, Nathaniel Pryor and William Bratton, enlist. In Washington City, the Senate ratifies the Louisiana Purchase treaty.
Spoiled smallpox vaccine
Cincinnati, OH Lewis writes a letter to President Thomas Jefferson. In it, he provides most of the information we have about his days in Cincinnati. He thanks Jefferson for sending a vaccine and asks the President to send a copy of the Louisiana Purchase treaty.
Pittsburgh arrival
Lewis arrives at Pittsburgh and immediately writes the President. In Washington City, Thomas Jefferson writes to Lewis with news of the Louisiana Purchase and information about the Columbia River.
Jefferson's letter of credit
The news of the Louisiana Purchase is made public and President Jefferson issues Meriwether Lewis an open letter of credit to pay for supplies or passage should he meet any ships at the Pacific Ocean.
News from France
A letter announcing that the Louisiana Purchase Treaty has been officially signed reaches Washington City. President Jefferson writes to Henri Peyroux, the former commandant of St. Genevieve.
Louisiana Treaty completed
In Paris, France, Robert Livingston and James Monroe record the details of the Louisiana Purchase for James Madison. Also in Paris, B. G. É. L. Lacepède provides information about the Columbia River.
Louisiana Treaty signed
The French-language version of the Louisiana Purchase Treaty and Convention is signed in Paris, France, and Robert Livingston writes to President Thomas Jefferson to tell him the news.
The price for Louisiana
In Paris, France, the Louisiana Purchase negotiators settle on a price—80 million francs plus payment of French debts worth about 20 million francs.
Kentucky militants
James Madison summarizes Spain’s request that he do something about the militants from Kentucky who are organizing to open the port of New Orleans by force. The Louisiana Purchase would ultimately result.
Up the Ouachita River
by Jay H. Buckley
While Lewis and Clark wintered in North Dakota, Dunbar and Hunter explored the Ouachita River in Arkansas. They would alter Jefferson’s plans to explore the Red and Arkansas Rivers.
This site is provided as a public service by the
Lewis and Clark Trail Heritage Foundation
with cooperation and funding from the following organizations:
Unless otherwise noted, journal excerpts are from The Journals of the Lewis and Clark Expedition, edited by Gary E. Moulton, 13 vols. (Lincoln: University of Nebraska Press, 1983-2001).