USA HISTORY

Detailed explanation-1: -Thomas Jefferson was elected to the presidency in 1800. Two years later, he decided to organize an official, government-sponsored expedition to explore the upper reaches of the Missouri River and by so doing to find the elusive Northwest Passage to the Pacific Ocean.

Detailed explanation-2: -While at Fort Mandan, Lewis and Clark met French-Canadian trapper Toussaint Charbonneau and hired him as an interpreter. They allowed his pregnant Shoshone wife, Sacagawea, to join him on the expedition. Sacagawea had been kidnapped by Hidatsa Indians at age 12 and then sold to Charbonneau.

Detailed explanation-3: -Missouri Basin and Arkansas-Rio Grande-Texas Gulf Regions On May 14, 1804, Meriwether Lewis, William Clark and their group of 40 men, collectively known as the Corps of Discovery, launched their pirogues and keelboat onto the Missouri River at its mouth, some 18 miles from the young town of St. Louis.

Detailed explanation-4: -No exploration of the Oregon Country has greater historical significance than the Voyage of Discovery led by Meriwether Lewis and William Clark.

Detailed explanation-5: -They wanted to find the source of the Missouri. Lewis traveled ahead of Clark, and on June 13 found the waterfall of which the Native Americans had warned him. He sent word to Clark that he had found the waterfall, and, therefore, they had chosen the correct river to follow. In all, Lewis found five waterfalls.