Answer:
Lewis and Clark
Step-by-step explanation:
After the Louisiana Purchase in 1804, the President of the United States at the time: Thomas Jefferson, wanted to explore the territory that was purchased as soon as possible. So, he sent Meriwether Lewis and William Clark on a 2 year journey that lasted from 1804 to 1806. The expedition was roughly 8,000 miles long and it provided lots of new information about the region.