In 1804, Meriwether Lewis and William Clark led a group called the Corps of Discovery on a journey west. President Thomas Jefferson gave the group several jobs. They were to map the land, study plants and animals, look for a water route to the Pacific Ocean, and meet with Native nations.
As the Corps traveled west, they met many Indigenous peoples. Native nations had lived on these lands for generations and knew the land well. Indigenous people gave the Corps information about rivers and trails. They also provided food, horses, directions, and other help.
Lewis and Clark kept journals about their journey. They wrote about the land, plants, animals, and Native nations they met. They also made maps of their route. The Corps reached the Pacific Ocean in 1805 but did not find a water route across the continent.
The Corps returned in 1806. Their maps and journals gave the U.S. government more information about western lands. This information later helped U.S. settlers move west into lands where Native nations already lived.
