Why is the Lewis and Clark expedition so important TODAY?
They were the first people to explore the whole western half of what is today the United States that had been bought in the Louisiana Purchase. No one had really explored the area prior to that (except for the Native Americans that lived there of course). Today, people now live in the area that they explored. Over time, people came to the area, settled it, and the area became divided into the states that we know. EDIT: Lewis and Clark did NOT make the country bigger. Jefferson purchased the territory (or I guess the United States under Jefferson’s presidency) and Jefferson HIRED Lewis and Clark to explore the newly purchased area.