Meriwether Lewis was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 explorer, soldier

Soldier

A soldier is a member of the land component of national armed forces; whereas a soldier hired for service in a foreign army would be termed a mercenary...

, and public administrator, best known for his role as the leader of the Lewis and Clark Expedition

Lewis and Clark Expedition

The Lewis and Clark Expedition, or ″Corps of Discovery Expedition" was the first transcontinental expedition to the Pacific Coast by the United States. Commissioned by President Thomas Jefferson and led by two Virginia-born veterans of Indian wars in the Ohio Valley, Meriwether Lewis and William...

 also known as the Corps of Discovery, with William Clark. Their mission was to explore the territory of the Louisiana Purchase

Louisiana Purchase

The Louisiana Purchase was the acquisition by the United States of America of of France's claim to the territory of Louisiana in 1803. The U.S...

, establish trade and sovereignty over the natives near the Missouri River, and claim the Pacific Northwest and Oregon territory for the United States before European nations.