Overview

One of the greatest feats of exploration in North America was that undertaken by Lewis and Clark's Corps of Discovery from 1804-1806. During their travels, the Corps of Discovery explored the Mississippi and Missouri river basins, made scientific discoveries about many plant and animal species new to science, contacted Native American tribes, and helped cement the United States' claim to parts of the Pacific Northwest, formerly claimed by Great Britain and Russia.

Background

In a move of questionable legality and constitutionality, President Thomas Jefferson (1743-1826) purchased the Louisiana Territory from the French in 1803. The territory, stretching from New Orleans to Canada and encompassing the majority of the drainage basins of the Missouri River and west of the Mississippi River, increased the size of the United States dramatically. Although the Louisiana Territory proved a...