What there mission was:
Their mission was to explore the unknown territory, establish trade with the Natives and affirm the sovereignty of the United States in the region. One of their goals was to find a waterway from the US to the Pacific Ocean.
Impact of the Lewis and Clark expedition:
The expedition opened up new territory for the fur and lumber trade and pointed out the best lands for future settlement and agriculture. It allowed a young country to blossom into greatness, because more land had equated to more resources and therefore, more power. The influence of the expedition is incalculable.
Who Lewis and Clark met along the way:
Lewis and Clark met Charbonneau and quickly hired him to serve as interpreter on their expedition. Even though she was pregnant with her first child, Sacagawea was chosen to accompany them on their mission. Lewis and Clark believed that her knowledge of the Shoshone language would help them later in their journey.