Noun
an expedition sent by Thomas Jefferson to explore the northwestern territories of the United States; led by Meriwether Lewis and William Clark; traveled from St. Louis to the mouth of the Columbia River from 1803 to 1806
Source: WordNetThe ultimate camping trip was the Lewis and Clark expedition. Dave Barry
I think the Lewis and Clark Expedition was the greatest undertaking in American History. I think landing a man on the moon pales next to it. Kathryn Lasky
After the United States acquired the Louisiana Purchase in 1803 and conducted the Lewis and Clark Expedition in 1804-1806, more information about the Plains became available and various pioneers entered the areas. Source: Internet
From 1805 to 1807, the Lewis and Clark Expedition entered the Oregon Country along the Clearwater and Snake rivers, and encountered numerous small settlements of natives. Source: Internet
Many of these later explorers were original members of the Lewis and Clark Expedition who had returned to map and explore the area in greater detail. Source: Internet
Online Etymology Dictionary The 1804 journals of the Lewis and Clark Expedition note that in September 1804, they "discovered a Village of an animal the French Call the Prairie Dog". citation Its genus, Cynomys, derives from the Greek for "dog mouse". Source: Internet