What was the purpose of the Lewis and Clark expedition?

The purpose of the Lewis and Clark expedition was to discover the western half of North America

The purpose of the Lewis and Clark expedition in 1804-1806 was the first American expedition to explore the west, and map the newly acquired territory. They also wanted to find a practical route, and establish themselves. Studying the wildlife - plants, animals, etc - and establish trade with local indians was also an objective of the expedition!