1. They were the first Europeans to cross the Rocky Mountains and reach the Pacific Ocean. In 1804, President Thomas Jefferson sent Meriwether Lewis and William Clark on an expedition to explore the Louisiana Territory, which had recently been purchased from France. The Lewis and Clark Expedition lasted for two years and four months, and covered over 8,000 miles.
2. They encountered many different Native American tribes along the way. The Lewis and Clark Expedition met with dozens of different Native American tribes, including the Shoshone, Nez Perce, and Flathead tribes. They learned about the different cultures and customs of these tribes, and they also relied on their help to navigate the wilderness.
3. They collected a vast amount of scientific information. Lewis and Clark were not only explorers, but they were also scientists. They collected thousands of specimens of plants, animals, and minerals, and they also made detailed observations about the geography and climate of the regions they passed through. Their findings were published in a series of books, which helped to increase scientific knowledge about the American West.