What was the purpose of the Lewis and Clark expedition?

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!

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