The modesty of the request, couched principally in terms of promoting commerce, belied the grandeur of the vision behind it. Jefferson had long been fascinated with the West and dreamed of a United States that would stretch across the entire continent.

Jefferson instructed Meriwether Lewis, who commanded the expedition jointly with William Clark, to seek new trade routes, to befriend the western tribes of Indians, and to report on the geography, geology, astronomy, zoology, botany, and climate of the West. The 8,000-mile expedition provided the U.S. Government with its first glimpse of the vast lands that lay west of the Mississippi River.

President Jefferson worked closely with Meriwether Lewis to ensure that he was well prepared—anticipating what the party would need in the way of arms, food, medicines, camping gear, scientific instruments, and presents for the Indians. They planned well. While the expedition ran out of such luxuries as whiskey, tobacco, and salt, they never ran out of rifles and powder, needed both for self-defense and food supply—and they never ran out of ink and paper, needed to record their findings.

For more information and other documents from the Lewis and Clark expedition, visit the Expansion and Reform section of the National Archives' American Originals exhibition.

(Information excerpted from Stacey Bredhoff, American Originals [Seattle: The University of Washington Press, 2001], p. 28.)