Marco Polo, with his father and uncle, spent years traversing the Silk Road. During their travels, the Polos gained both great wealth and knowledge of Central Asia and the Middle East that allowed Marco to publish his memoirs of his extensive travels, A Description of the World, in 1298. The book was of great interest to European traders and explorers.
Meriwether Lewis and William Clark explored the territories gained through the Louisiana Purchase. The Corps of Discovery set out from St. Louis and explored 8,000 miles along the Missouri and Columbia Rivers and reached the Pacific. The expedition returned in 1806.