Sacagawea, the Shoshone interpreter and guide to the Lewis and Clark expedition, gives birth to her first child, Jean Baptiste Charbonneau.

Hans Christian Andersen, one of the world’s greatest storytellers, is born in Odense, near Copenhagen.

After a long winter, the Lewis and Clark expedition departs its camp among the Mandan tribe and resumes its journey West.

After marching 500 miles from Egypt, U.S. agent William Eaton leads a small force of U.S. Marines and Berber mercenaries against the Tripolitan port city of Derna. The Marines and Berbers were on a mission to depose Yusuf Karamanli, the ruling pasha of Tripoli, who had seized power from his brother, Hamet Karamanli, a pasha who was sympathetic to the United States.

Having hurried ahead of the main body of the expedition, Meriwether Lewis and four men arrive at the Great Falls of the Missouri River, confirming that the explorers are headed in the right direction.

In one of the most decisive naval battles in history, a British fleet under Admiral Lord Nelson defeats a combined French and Spanish fleet at the Battle of Trafalgar, fought off the coast of Spain.

Having spied the Pacific Ocean for the first time a few weeks earlier, Meriwether Lewis and William Clark cross to the south shore of the Columbia River (near modern-day Astoria) and begin building the small fort that would be their winter home.