Lewis and Clark Expedition

Lewis and Clark Expedition

Meriwether Lewis and William Clark

The Lewis and Clark Expedition, also known as the Corps of Discovery Expedition, was the first American expedition to cross the western portion of the United States. It began in May 1804 and concluded in September 1806. The expedition was commissioned by President Thomas Jefferson shortly after the Louisiana Purchase in 1803. The primary objective was to explore and map the newly acquired territory, find a practical route across the western half of the continent, and establish an American presence before European powers attempted to claim it.

Background

In 1803, President Jefferson tasked his personal secretary, Meriwether Lewis, with leading an expedition to explore the lands west of the Mississippi River. Lewis selected William Clark as his co-leader. The expedition was to study the area's plants, animal life, and geography, and to establish trade with local Native American tribes.

Preparation

Reconstruction of Camp Dubois

The expedition was prepared at Camp Dubois in Illinois, where the Corps of Discovery was assembled. The team consisted of 33 members, including soldiers, civilians, and one Native American woman, Sacagawea, who served as an interpreter and guide.

Journey West

The expedition set out from Camp Dubois in May 1804, traveling up the Missouri River. They passed through what is now Missouri, Kansas, Iowa, and Nebraska, reaching the Mandan villages in present-day North Dakota by winter 1804.

Interior of Fort Mandan

At Fort Mandan, the expedition spent the winter of 1804-1805. Here, they met Chief Shehaka of the Mandan tribe and gathered valuable information about the terrain ahead.

Crossing the Rockies

In the spring of 1805, the expedition continued westward, crossing the Rocky Mountains with the help of Sacagawea and her tribe, the Shoshone. The journey through the mountains was arduous, but they eventually reached the Columbia River basin.

Lewis and Clark meeting the Flathead tribe

Reaching the Pacific

The expedition reached the Pacific Ocean in November 1805, establishing Fort Clatsop near present-day Astoria, Oregon. They spent the winter of 1805-1806 at Fort Clatsop, preparing for the return journey.

Replica of Fort Clatsop

Return Journey

In March 1806, the expedition began its return journey. They retraced their steps back across the continent, reaching St. Louis, Missouri in September 1806. The expedition was hailed as a success, having gathered extensive information about the western territories and established American claims to the Pacific Northwest.

Legacy

The Lewis and Clark Expedition provided valuable insights into the geography, biology, and ethnography of the western United States. It paved the way for westward expansion and was instrumental in the development of the American frontier.

Map of Lewis and Clark's track across North America

Related Pages

• Thomas Jefferson
• Louisiana Purchase
• Sacagawea
• Meriwether Lewis
• William Clark