Lewis and Clark Expedition Timeline
Timeline Description: Meriwether Lewis (born August 18, 1774) and William Clark (born August 1, 1770) under the supervision of President Thomas Jefferson, led a two and one-half year expedition across the Western United States, exploring, drawing maps, and working to develop relationships with Native American tribes.

Date Event
January 18, 1803 Jefferson Asked Congress to Fund the Expedition

President Thomas Jefferson secretly asked the U.S. Congress to approve and fund an expedition to the Western part of the continent. In the spring of 1803, Meriwether Lewis, Jefferson's personal secretary, began to train for his role as expedition leader.
July 4, 1803 The Louisiana Purchase

The Louisiana Purchase was announced. Much of the land west of the Mississippi is now part of the young United States. This made the expedition even more important than before, as it now provided the opportunity to learn more about land available for settlement.
1803 The Corps of Discovery Assembles(Summer 1803)

After he supervised construction of a keel boat, Lewis picked up William Clark and began the journey down the Ohio River, collecting other recruits. Lewis and Clark established Camp Wood on the banks of the Wood River in Illinois in the fall and winter of 1803. The Corps of Discovery, the name given to the Lewis and Clark Expedition, would winter there.
March 10, 1804 The Official Transfer of the Louisiana Purchase

Both Lewis and Clark attended the ceremony marking the transfer of lands purchased from France in the Louisiana Purchase. The ceremony took place in St. Louis.
May 14, 1804 The Corps of Discovery Left Camp Wood

Lewis and Clark officially left Camp Wood, setting out on the Missouri River, on May 14, 1804. They headed west in good weather.
August 3, 1804 Council with the Oto and Missouri Indians

Lewis and Clark held meetings near modern-day Omaha, Nebraska with members of the Oto and Missouri Tribes. Little was accomplished at this summit, and members of the Oto and Missouri tribes were dissatisfied.
August 30, 1804 Meeting with the Yankton Sioux

On August 30, Lewis and Clark met with the Yankton Sioux. Again, the meeting did not go well, and relations with the Sioux were often quite tense, nearly coming to a confrontation in late September 1804.
November 4, 1804 Lewis and Clark Hired Charbonneau and his wife, Sacagawea

In need of a translator, Lewis and Clark hired a French fur trader and his Shoshone wife to accompany them. The Corps of Discovery spent the winter of 1804 in Fort Mandan, located in modern North Dakota. William Lewis delivered Sacagawea's son while at the winter camp in February 1805.
April 7, 1805 First Shipment to the East

On April 7, 1805, the Corps of Discovery sent the first batch of specimens and artifacts from their journey west to President Jefferson. Most of the party continued on further west. By April 29, they were near the Yellowstone River in Montana.
1805 The White Cliffs of the Missouri River(Summer 1805)

On May 31, 1805, Lewis and Clark reached the White Cliffs of the Missouri River. The following day, they were faced with a choice of two forks in the river. By August 1805, they neared Shoshone lands, marked by Beaverhead Rock, and soon found the headwaters of the Missouri River. This confirms that there is no Northwest Passage across the continent.
August 31, 1805 The Bitterroot Mountains

After spending some time among the Shoshone, where Sacagawea's brother was Chief, they set out across the Bitterroot Mountains. The crossing was approximately 160 miles. They began their climb on September 11, 1805 and emerged on September 23, 1805. The journey across the mountains was difficult; however, everyone survived.
October 1805 The Clearwater and Columbia Rivers

Lewis and Clark, now in dugout canoes made in the manner of the Nez Perce tribe, set out on the Clearwater River, reaching the Columbia River on October 16. With the current of the rivers, the Corps of Discovery made excellent time, but did encounter dangerous rapids.
November 24, 1805 The Pacific Ocean

On November 7, 1805, Clark believed he could see the Pacific. He was incorrect, and was seeing the widening headwaters of the Columbia River. The team reached the Pacific on November 24. All members voted on the site for the winter camp that year, and the Corps of Discovery camped at Fort Clatsop during the winter of 1805.
March 23, 1806 The Journey Home Begins

Lewis and Clark handed over the camp they had constructed to the local Clatsop Indian tribe and set out on their return journey. The trip home was to be a much faster and easier one, thanks to new information about the land.
September 23, 1806 The Journey Ends

On September 23, 1806, Lewis and Clark, as well as the other members of the Corps of Discovery, were welcomed back to St. Louis. They carried not only the journals of their expedition, but also careful maps drawn by Clark during their journey.