F.A.Q

One main reason the Lewis and Clark expedition was called the Corps of Discovery is because a Corp is like am army, or a group of people within a militia. This expedition was a group of soldiers exploring trying to expand their knowledge and discover new things . 

Thomas Jefferson was the one who appointed Lewis to be the leader of the expedition. Since Lewis and Jefferson were neighborhood friends Jefferson knew he could trust Lewis. Lewis was also very invested in the government at the time so Jefferson knew he would be devoted and willing to fulfill his job. Lewis then sent a letter to Clark asking him to lead the expedition together. Lewis knew he could trust Clark because they were in the military together and had developed a friendship. 

Meriwether Lewis and William Clark. 

After Lewis and Clark got back from their expedition, they both got different jobs, and parted ways. After Lewis got back he became Governor of the Louisiana Territory in 1808. His great abilities as leader of the expedition, however, did not translate into a successful political career. He made enemies with other quickly and was instantly depressed. The next year in 1809, Lewis died, many people don't know how. Many think it was a suicidal act due to his depression but many aren't sure. He did not have time to raise a family or even get married. On the other hand Clark, did get married and had many kids. After the expedition ended, Clark traveled in to St. Louis to work as chief Indian agent for the Territory of Upper Louisiana. He decided to bring York with him, his slave.