Lewis, Meriwether (1774-1809), was a co-leader of the Lewis and Clark expedition. The other leader was William Clark. The expedition explored the Louisiana Territory and the Oregon region from 1804 to 1806.
In 1801, Lewis, a captain in the United States Army, became private secretary to United States President Thomas Jefferson. Under Jefferson’s direction, Lewis made plans to explore a route west to the Pacific coast of North America. Lewis invited Clark to join the expedition. The two men privately agreed to lead it jointly. Lewis served as the party’s naturalist. He collected plant, animal, and mineral specimens.
The Louisiana Territory was a vast area between the Mississippi River and the Rocky Mountains. It stretched from the Gulf of Mexico to Canada. The Oregon region included a large area between the Rocky Mountains and the Pacific coast. Jefferson believed that a route could be found to the Pacific coast along the Missouri and Columbia rivers. Such a route could be part of a land-and-water passage between the Atlantic and Pacific oceans.
The expedition started up the Missouri River in May 1804 from a camp near St. Louis. By late fall, the explorers had reached what is now North Dakota. They spent the winter there. The following spring, they continued along the Missouri. In late summer, they crossed the Rocky Mountains. The explorers then followed the Clearwater and Snake rivers to the Columbia River. They reached the Pacific coast in November 1805. They spent the winter on the coast of what is now Oregon. They began the trip home in March 1806. The party returned along nearly the same route by which they had come. They reached St. Louis in September 1806.
The expedition’s success enabled the United States to claim the Oregon region. This area included what are now the states of Oregon, Washington, and Idaho. As a reward for his service, Jefferson named Lewis governor of the Louisiana Territory in 1807. On Oct. 11, 1809, Lewis probably committed suicide. Personal and professional problems may have caused the suicide. But some people believe that he was murdered.
Lewis was born on Aug. 18, 1774, in Albemarle County, Virginia. He joined the U.S. Army in 1794. He rose to the rank of captain in 1800.
See also Clark, William ; Lewis and Clark expedition .
