The purpose of the Lewis and Clark expedition had the same purpose like many other expeditions: To explore unknown territories, establish trade with natives, show ownership
*In 1803 when the U.S purchased Louisiana from France, president Jefferson wanted to examine the land before settling there so he sent Lewis to be in charge of the expedition, and he invited Clark to come along
They also wanted to find a water way from the U.S to the Pacific
* The U.S also wanted to show that they owned the territory before other powers tried to claim it