The Lewis and Clark Expedition (1804-1806) was the first United States expedition to the Pacific Coast. Commissioned by President Thomas Jefferson and led by Meriwether Lewis and William Clark, the expedition had several goals. According to Jefferson himself, one goal was to find a "direct & practicable water communication across this continent, for the purposes of commerce" (the Northwest Passage). In order to make a firm claim of “discovery” to the Pacific Northwest and compete with the British for control of land and the fur trade, Jefferson had the men follow the rivers, map them, and collect scientific data. Jefferson also placed special importance on declaring U.S. sovereignty over the Native American tribes along the Missouri River, and getting an accurate sense of the resources in the recently-completed Louisiana Purchase. Although the expedition did make notable achievements in science, scientific research itself was not the main goal behind the mission.
References to Lewis and Clark "scarcely appeared" in history books even during the United States centennial in 1876 and the expedition was largely forgotten despite having had a significant impact on increasing American owned land.