Respuesta :
Answer:
President Thomas Jefferson commissioned the expedition shortly after the Louisiana Purchase in 1803 to explore and to map the newly acquired territory, to find a practical route across the western half of the continent, and to establish an American presence in this territory before Britain and other European powers.
Explanation:
To find more land and expand the land. In order to expand he needed to know what was out there. Lewis and Clark found many species of new things.