Due to the devastation of WWII the Marshall plan was to help rebuild western Europe economically and financially, because the US wasn't neutral in the war anymore.<span />
United states was successful in purchasing many thousands square miles of land from France and it was called Louisiana Purchase. But most of the lands which were bought were not being explored and hence under the term of Thomas Jefferson, congress granted permission to Meriwether Lewis and William Clark to undertake an expedition to explore the west.
Explanation:
The corps left from St. Louis harbored near Mississippi and explored Portland and Oregon, they wrote the first report to Thomas Jefferson regarding the encounter of various Native american tribes and about 108 new plants and animal species that were found in the west. The confrontation with the Tetons and Sioux, tribes were largely peaceful and thus it paced way for them to study the geography and the cultural differences of the native Americans who resided in the great plains of West. Lewis and Clark expedition provided a great knowledge about the Geographical, physical and cultural features of the west and they produced around Hundred and forty maps which helped the future people to explore the west.
The answer is C. Sacajawea.
good luck!
