Meriwether Lewis (August 18, 1774 – October 11, 1809)

Lewis was an American explorer, soldier, and public administrator, who
was the leader of the Lewis and Clark Expedition that, along with William
Clark, explored the territory of the Louisiana Purchase, establish trade
and sovereignty over the natives near the Missouri River, and claimed
the Pacific Northwest and Oregon Country for the United States. He
was also the second Governor of the Louisiana Territory, appointed
by President Thomas Jefferson.  

Lewis and Clark with Sacagawea

The Lewis and Clark expedition at Fort Clatsop in Oregon

The winter encampment at Fort Clatsop National Park today