Little Known Facts - 4

“The Lewis & Clark Expedition and the Louisiana Purchase”

There is a durable popular notion that the Lewis and Clark Expedition was originally fielded for the purpose of exploring the Louisiana Purchase. Well . . . . . .
Yes and No. Actually, it was set in motion by President Thomas Jefferson months before the United States even knew France was willing to sell the vast western wilderness known as Louisiana and before the 15 million dollar deal was struck by America’s negotiators in Paris at the end of April 1803.

In a secret message to Congress on January 18, 1803, Jefferson sought congressional authorization of an expedition into the trans-Mississippi area “for the purpose of extending the external commerce of the U.S.” As originally conceived, the venture was to consist of 10 to 12 military volunteers and a commanding officer. The initial emphasis on confidentiality reflected concern for the fact the expedition would be operating in foreign-controlled territory (which was true at the time). Congress approved the president’s request and appropriated $2,500 to fund the secretive operation.

After Meriwether Lewis, the president’s personal secretary, was appointed commanding officer of the expedition, he spent the next five or so months making preparations to take his command into the field. He acquired weapons and related accoutrements and collected a small mountain of supplies and equipment, including a wide range of Indian gifts and trade goods to smooth his way westward. It was during that time, at the behest of President Jefferson, Lewis also received tutorials in botany, biology, medicine and celestial navigation from some of the nation’s leading natural scientists in Philadelphia.

On July 4, 1803, a day before Lewis pushed off from Washington, D.C. for Pittsburgh where he was to take possession of his flagship, a specially designed 55-foot keelboat, President Jefferson received official confirmation of the signing of the Louisiana Purchase treaty between France and the U.S. That stunning development changed the whole complexion of the expedition, effectively shifting it from a military reconnaissance into a foreign-controlled region to that of an exploration of Americanowned territory (at least to the Continental Divide). Only at that point was the Lewis and Clark Expedition committed to exploring key portions of the Louisiana Purchase and beyond.

Dr. H. Carl Camp


Stephen E. Ambrose, Undaunted Courage: Meriwether Lewis, Thomas Jefferson, and the Opening of the American West (New York: Simon & Schuster, 1996), pp. 59-l01.

Roy E. Appleman, Lewis and Clark’s Transcontinental Expedition, 1804-1806 (Washington, D.C.: United States Department of the Interior, National Park Service, 1975), pp. 28-49.

Last updated: December 13, 2016

Contact the Park

Mailing Address:

601 Riverfront Dr.
Omaha, NE 68102


(402) 661-1804

Contact Us