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featuring 28 men and one woman—a Native American named Sacagawea—left St. Louis for the American interior.
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News of the Louisiana Purchase is announced; Lewis will now be exploring land largely owned by the United States.
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Sergeant Charles Floyd dies of natural causes near present-day Sioux City, Iowa; he will be the only fatality among the Corps of Discovery during the expedition.
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The men record the temperature at 45 degrees below zero, "colder than [they] ever knew it to be in the States."
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Sacagawea's son, Jean Baptiste Charbonneau—nicknamed Pompy by Clark—is born with assistance from Lewis.
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Jefferson receives the shipment from Fort Mandan; Lewis finds the headwaters of the Missouri River, then crosses the Continental Divide and Lemhi Pass to discover that there is no Northwest Passage.
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The Corps begins the steep ascent into the Bitterroot Range of the Rocky Mountains; the crossing will cover more than 160 miles (260 kilometers).
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The expedition reaches the Columbia River, the last waterway to the Pacific Ocean.
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The expedition reaches the Columbia River, the last waterway to the Pacific Ocean.
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After two and a half years, the expedition returned to the city, bringing back a wealth of information about the largely unexplored region, as well as valuable U.S. claims to Oregon Territory.
Having found an easier route across the country, the men reach St. Louis nearly two and a half years after their journey began and are acclaimed as national heroes.