On January 18, 1803, Thomas Jefferson requests funding from Congress to finance the Lewis and Clark expedition.

Jefferson officially asked for $2,500 in funding from Congress, though some sources indicate the expedition ultimately cost closer to $50,000. Meriwether Lewis was joined by his friend William Clark and 50 others on the journey, including an enslaved African American and a female Native American guide named Sacagawea. The team, which Jefferson called the Corps of Discovery, first surveyed the territory that comprised the Louisiana Purchase, a vast expanse that reached as far north as present-day North Dakota, south to the Gulf of Mexico and stopped at the eastern border of Spanish territory in present-day Texas. The team then crossed the Rockies and navigated river routes to the Pacific coast of present-day Oregon. Upon their return, the duo’s reports of the exotic and awe-inspiring new lands they had encountered sparked a new wave of westward expansion.

Jefferson first proposed the exploratory expedition even before Napoleon offered to sell France’s American territory, which would become known as the Louisiana Purchase, to the United States and had authorization from Congress to launch a survey of the area when news of Napoleon’s offer to sell reached Washington. In a stroke of luck for the United States, Napoleon had abandoned plans to establish a French foothold on America’s southern flank and sold the land to the U.S. to subsidize his conquest of Europe.

Though he did not disclose his intentions to Congress, Jefferson planned to send Meriwether Lewis, his private secretary, on a reconnaissance mission that far exceeded the boundaries of the Louisiana Purchase to determine how far west the U.S. might extend commerce in the North American fur trade and to assess the viability of future territorial expansion into the west. In misleading Congress, Jefferson had temporarily stifled his distaste for abuse of executive privilege to achieve a strategic goal. A product of the Enlightenment, Jefferson was a man with strong political principles, but he was also fascinated by what the expedition might yield in terms of scientific discovery and adventure. Jefferson sought to claim more territory for the United States, eliminate foreign competition and convert the Indian nations to Christianity, viewing westward expansion as a way for the nation to maintain its agrarian values and to ward off the same political perils that plagued what he saw as an increasingly overcrowded Europe.