When President Thomas Jefferson sent Meriwether Lewis, William Clark and a company of men up the Missouri River and into the terra incognita of the lands newly acquired in the Louisiana Purchase, the young United States already had a Constitution, but it lacked an epic vision. It had a government but no real identity. Lewis, Clark and their Corps of Discovery helped invent one — with the essential assistance of a young Indian woman, Sacagawea.
The Native American, pregnant at 16, was the wife of Toussaint Charbonneau, a fur trapper serving the expedition as a guide; she was valued for her knowledge of the Shoshone language. Clark helped her give birth inside a wintry fort, and she repaid him a thousand times over by arranging with her Indian kinsmen for the expedition’s safe passage over the Rockies. As Clark noted in his diary, “The sight of this Indian woman … confirmed those people of our friendly intentions.”
(SPECIAL: Lewis & Clark: The Ultimate Adventure)
Lewis and Clark kept perhaps the most complete journals in the history of human exploration (some of which survived only because Sacagawea jumped into a stream to retrieve them when a canoe capsized). We can look over their shoulders as they and their party contend with hunger, disease, blizzards, broiling sun, boiling rapids, furious grizzly bears and plagues of “musquetors.” When their party returned to St. Louis after 26 months on the road, the blank spaces on the American map had been filled in — and the nation’s continental destiny beckoned.
This entry is excerpted from the new TIME book The 100 Most Influential People of All Time, which profiles spiritual icons, leaders, explorers, visionaries and cultural titans throughout human history. Available wherever books are sold and at time.com/100peoplebook
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