Lewis and Clark had three goals for their expedition: explore unknown territories, promote the sovereignty of the United States and its government, and establish trade with Native Americans. Lewis, Clark, and their men were successful in a large number of their dealings with Natives.
They had a protocol for initial contact which included presenting the chief of the tribe with a "Peace Medal" coin from President Jefferson. They also presented Native tribes with gifts such as beads, tobacco, bright cloth, mirrors, and knives. They told the Natives that their land was owned by America and that the government was willing to offer them protection in exchange for peace. Along the way some Natives were open and friendly- while others were fearful and hostile.