Meriwether Lewis and William Clark led the government-commissioned expedition to explore the newly-acquired Louisiana territory. Their exploration team was known as the Corps of Discovery. The Corps set out from St. Louis, Missouri in 1804 and returned in 1806, having covered 8,000 miles in two years.
As Lewis and Clark explored, they gathered information on the landscapes, plants, animals and Native Americans they met on their journey. Their journals recorded 180 plants and 125 animals that were new to scientists. The explorers traveled west to the Pacific Ocean off the present-day Oregon coast. Their expedition helped the United States government understand the potential of its purchase and opened up the territory for pioneers to settle.