Explorers had searched without success to find an all water route across North America. President Jefferson believed one existed and he made finding the route the main goal of Lewis and Clark's expedition. If found, this route would open up trade with China and India and eliminate the long, risky trip of sailing around the tip of South America to reach those countries.

President Jefferson thought the Corps would be able to travel by boat up the Missouri River, make a short crossing over the Rocky Mountains to the Columbia River, and then float down the Columbia to the Pacific Ocean. The journey began in May 1804 and ended in September of 1806. It took Lewis a whole year to prepare for it.



Lewis spent the Spring of 1803 training to lead the expedition. He studied navigation under mathematicians and astronomers Andrew Ellicott and Robert Patterson, medicine under Dr. Benjamin Rush, surveying with Robert Patterson, and botany and zoology under Dr. Benjamin Smith Barton.

Lewis was given a special map of the western United States by Albert Gallatin, Jefferson's Secretary of the Treasury. It had only three known points on it: the city of St. Louis, Missouri, the Mandan Indian villages on the upper Missouri River, and the mouth of the Columbia River. Lewis would have to fill in the blanks as he went along.

After spending most of the summer waiting for a special keelboat to be built, Lewis finally left Pittsburgh, Pennsylvania, on August 31, and headed down the Ohio River to meet his co-captain, William Clark. Low water levels made the trip down the river frustrating and slow. The large keelboat, which Lewis named the Discovery, kept getting stuck on sandbars. Many times Lewis had to find a local farmer with a team of oxen that could pull it over the sandbars. Lewis finally purchased a pirogue to carry some of the keelboat's load.

Lewis began collecting and classifying plant and animal specimens as soon as the trip began. He used the skills taught to him by Dr. Barton to gather seeds, preserve specimens (samples), and label them with the date and place where they were found. This may sound like an easy task, but think about it for a minute. If you were in a new land and saw things you had never seen before, how would you start to classify (sort) them?

On October 14, 1803, Lewis' party finally reached Clarksville, Indiana, and joined Clark.

Together with the men hired for the expedition, they headed down the Ohio towards the mighty Mississipi River. The current of the Mississipi proved much stronger than the Ohio and slowed their travel down to a few miles a day.

On December 12, 1803, the expedition reached the Wood River, just past the frontier town of St. Louis. Lewis and Clark thought this would be a good spot to set up camp for the winter. The men built a cluster of log cabins - quarters for the men, one for blacksmithing, and one for a storehouse. During the winter, Clark trained the men. They practiced shooting and even had shooting contests with the local settlers that stopped by (the settlers usually won!). They also practiced marching, which no one liked very much. While they were at Camp Wood, the Louisiana Territory was officially transferred to the United States from France.

Lewis often traveled to St. Louis during the winter to make final preparations for the journey, so it was up to Clark and his sergeants to begin the expedition.


On May 14, 1804, the Corps of Discovery left Camp Wood. The men were in good spirits as they left behind the only world they knew and set out into unknown lands. Clark wrote in his journal: "Rained the fore part of the day. I determined to go as far as St. Charles, a French village seven leagues up the Missouri, and wait at that place until Captain Lewis could finish the business which he was obliged to attend to at St. Louis, and join me by land...I set out at 4 o'clock, P.M., in the presence of many of the neighboring inhabitants and proceeded under a gentle breeze up the Missouri to the upper point of the first island, 4 miles, and camped on the island."

They traveled upstream in the keelboat and two pirogues until they reached St. Charles, Missouri. Lewis rode overland and joined them on May 20. On May 21, 1804, the expedition left St. Charles at 3 p.m.

Each day of the journey began at dusk with a cold breakfast (no cooking was allowed during the day because it took too long). Some of the men would walk or ride along the shore to hunt for food, while the others traveled in the keelboat and pirogues. It was hard work for the men in the boats to keep them moving upstream. They could row, pole, or drag them by ropes. If they were lucky, they could sail against the current. Sudden storms, trees floating in the water, and collapsing banks were all threats to the boat crews.

Captain Lewis spent most days walking along the shore with his dog, Seaman. He observed the plants and animals that he encountered, and collected specimens of those that could not be found in the east. His journal was always handy for descriptions and drawings.

Captain Clark, on the other hand, stayed in the keelboat and directed the men. He also made careful notes along the way of the twists and turns of the river. At the end of the day, Clark would survey the land where they were camped, note landmarks, streams, and the weather, and draw maps. Together, the captains would make lunar observations and note the positions of stars.

Each night the men were wet and exhausted, but there was still work to be done before they rested. There were tents to be pitched, firewood to gather, and the only hot meal of the day to be prepared. Each man was given food and whiskey for supper. After they ate, the men dried the meat that had been caught that day, repaired clothes, or carved new oars for the boats.

By August, the expedition had still not seen any of the great herds of buffalo or the Indians that fur traders talked about. Finally, on August 2, 1804, a small group of Oto (OH-toe) and Missouri (ma-ZOO-ree) Indians visited their camp. These tribes were farmers as well as hunters, and they brought "Water millions" (Clark's spelling of watermelons) for the men. Lewis and Clark invited them to bring their chiefs for a council (large meeting) the next day.

Meetings or "councils" with the Indian tribes they met, required some preparation by the Corps. The Captains dressed in their fanciest dress coats and three-cornered hats. The men performed military drills. Lewis would then give a speech explaining that the United States now owned the land and the President was now their new "father" and would take care of them. The chiefs were presented gifts of tobacco, dye, gunpowder, and peace medals.

On August 18, 1804, near modern Homer, Nebraska, Captain Lewis celebrated his 30th birthday. He didn't celebrate long, however, one of the men, Private Moses Reed, tried to desert the Corps. Reed was caught and brought back to camp. In the military at that time, desertion was punishable by death, and men accused of this act were tried by court martial - a military court made up of members of the Corps. Reed was found guilty and was sentenced to "run the gauntlet" four times. This meant that he had to walk between two rows of men as each one whipped his bare back. Private Reed also lost his place in the Permanent Party.

A few days later on August 20, 1804, near Sioux City, Iowa, Sergeant Charles Floyd died. He had been feeling sick for several days, and nothing Captain Lewis tried to cure him worked. It's thought that he died from appendicitis, so even if Lewis had known this, there was nothing he could have done to save him (the first operation to remove an infected appendix was not performed until the 1880s). Floyd was buried with military honors on a bluff above the Missouri river.

August proved to be a bad month for the Corps. Not long after Sergeant Floyd was buried, Private George Shannon was lost. He had been sent out with Drouillard to look for the Corps' horses. Drouillard returned the next day, but Shannon did not. The Corps continued upriver, hoping that Shannon was safe and would be found later. After 16 days, the keelboat crew spotted Shannon sitting along the riverbank, weak and starving. He had actually passed the Corps, thinking they were far ahead of him!

The expedition came upon the Yankton Sioux Indian tribe on August 30 and held council with them. Lewis and Clark had heard about the Sioux. They traveled with the seasons, following the buffalo herds. The Sioux were excellent riders and used their swift horses to hunt buffalo for food, clothing, and shelter.

After a short stay with the Yankton Sioux, the expedition set out again on September 7. They saw many new animals as they traveled. One day they saw hundreds of squirrel-like animals standing on mounds in the short prairie grass. The animals disappeared quickly when the men approached. Their dog-like bark inspired their name - prairie dogs. Mule deer, white-tailed jackrabbits, and pronghorn antelopes (the fastest animal in North America), were also seen for the first time.

On September 25, the Corps encountered the Teton Sioux who were not as friendly as the Yankton. The Teton had traded with the English and pretty much controlled traffic on the Missouri. They weren't too happy about giving up their control to the "great chief" of the United States. After the usual council, the Tetons decided they wanted more gifts than what they had received. They refused to let the Corps leave. There was a tense standoff and weapons were drawn. Finally, one of the chiefs, Black Buffalo, allowed the Corps to go unharmed.

The expedition continued onward through modern-day South Dakota where they came upon an Arikara Indian village. They spent five days with the Arikara who were fascinated by York. White fur traders had visited their village, but they had never seen a black man. They left on October 12, and headed into North Dakota.

On October 25, the Corps reached the first of five Mandan villages just past what is now Bismarck, North Dakota. About 4,000 people of the Mandan and Hidasta tribes lived in the villages, and many of them flocked to see the white men.

The captains chose the east bank as the site of their winter camp. On November 3, the men began to build Fort Mandan. They constructed two rows of huts out of cottonwood trees, four huts to a row, and joined at one end to form an angle. They also built two large store rooms and surrounded all the buildings with an 18-foot tall fence for protection. They finished their work three weeks later, and just in time - seven inches of snow fell that night.

On November 4, the captains hired Toussaint Charbonneau and his Shoshoni wife, Sacagawea, as interpreters for the coming journey. Sacagawea, about 16-years-old at the time, was soon to give birth to her first child.

The winter at Fort Mandan was a cold one. Sergeant Ordway wrote in his journals that it "was colder than I ever [knew] it to be in the States." On December 6, the Missouri river froze over, and by the 17th, the temperature had dropped to 43 degrees below zero!

Christmas Day came and the men announced it with a bang. They fired their guns three times as they raised the flag over the fort. Lewis and Clark allowed the men special rations so that they could celebrate Christmas "in a proper and social manner." And they did. After eating, they sang and danced into the night.

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