Answer:
1. Louisiana Purchase a treaty signed with France in 1803 by which the U.S. purchased for $15,000,000 the land extending from the Mississippi River to the Rocky Mountains and from Canada to the Gulf of Mexico.
2. Sacagawea "Bird Woman", 1787?–1812?, Shoshone guide and interpreter: accompanied Lewis and Clark expedition 1804–05
3. Lewis and Clark expedition known as the Corps of Discovery Expedition, was the United States expedition to cross the newly acquired western portion of the country after the Louisiana Purchase.
4. Zebulon Pike was an American brigadier general and explorer for whom Pikes Peak in Colorado was named.
5. William Clark was an American explorer, soldier, Indian agent, and territorial governor.