He worked for a time as a fur trapper with the North West Company. It is while thus employed that he enters the historical record, in the journals of the recorder of an expedition of the NWC, John MacDowell. After several routine mentions of Charbonneau, MacDowell writes on May 30, 1795: "Tousst. Charbonneau was stabbed at the Manitou-a-banc end of the P. l. P. in the act of committing a Rape upon her Daughter by an old Saultier woman with a Canoe Awl—a fate he highly deserved for his brutality— It was with difficulty he could walk back over the portage". ["P. l. P." indicates Portage la Prairie, Manitoba.]
It was probably during the period of his employ with the North West Company that he first encountered the established settlement of Mandan and Hidatsa tribes on the upper Missouri River, in what today is North Dakota. He settled amongst these tribes, according to his own report around 1797, and the area would remain his home for the rest of his life. At that point he became a free agent, working on his own and for several different companies operating in the area, as a trapper, as a laborer, and as an interpreter of the Hidatsa language.
Soon after arrival at this settlement, Charbonneau purchased two captive Shoshone women from the Hidatsa, Sacagawea and "Otter Woman." These two young women had been captured by the Hidatsa on one of their annual raiding and hunting parties to the west. Charbonneau eventually considered these women to be his wives, though whether they were bound through Native American custom or simply through common law is indeterminate.
Sacagawea became pregnant with their first child in 1804, and it was during this year also that Meriwether Lewis and William Clark came to the area, built Fort Mandan, and recruited additional members to the Corps of Discovery. Charbonneau was interviewed for a position interpreting Hidatsa. Lewis and Clark, however, were not overly impressed with him; Charbonneau spoke no English and, although there were several in the party who could translate from French, an additional problem was that he did not even know Hidatsa all that well (by his own admission, over thirty years later, he still could not speak the language well after having lived with the Hidatsa during all that time). However, when it was discovered that his wives were Shoshone, Lewis and Clark were keen to have an interpreter for this language as well, and Charbonneau was therefore hired on November 4. He and Sacagawea moved into Fort Mandan a week later.
During the winter, Charbonneau communicated with members of the North West Company, and brought information back to Lewis' and Clark's company (during this period the situation between Britain and the United States was tense, and the group was concerned about how the British presence in the area would affect their group). Charbonneau's and Sacagawea's son Jean Baptiste was born during the winter at the fort, on February 11, 1805.
In the spring, as the expedition was preparing to get underway, Charbonneau had second thoughts about his role with the group. On March 12, 1805 it is recorded that he quit the expedition, having said he was dissatisfied that he would be required to stand guard, perform manual labor, etc. However on March 17 he returned and apologized, saying he would like to re-join the company; he was re-hired the following day.
At age 37, Charbonneau was the oldest member of the expedition. His performance during the journey was mixed: Meriwether Lewis called him "a man of no peculiar merit" and many historians paint Charbonneau in a distinctly unfavorable light, in no small part due to the rape incident mentioned above. Most of Charbonneau's positive contributions to the expedition itself were overshadowed by the incident with the "white pirogue."
The incident was presaged by one recorded in the journals on April 15, 1805, only a few days after the journey had set out. A sudden wind rocked his boat, and Charbonneau panicked; fortunately George Drouillard grabbed the tiller and righted the boat before a major incident, but the episode demonstrated that Charbonneau probably did not know how to swim (a decided detriment on a long river voyage).
A similar, more serious incident occurred about a month later. In the journals for May 14, 1805 it is recorded that the pirogue driven by Charbonneau was again hit by a squall. He again lost control of himself; Pierre Cruzatte, in the boat with him, threatened to shoot him if he did not regain his composure, but to no avail. The boat was nearly capsized, and equipment and papers were nearly lost into the river. Meriwether Lewis was irate, writing that Charbonneau was "perhaps the most timid waterman in the world."
Charbonneau, however, made several contributions to the success of the expedition. He was helpful when the expedition encountered French trappers from Canada, and he also served as a cook; his recipe for boudin blanc (a sausage made from bison meat) was praised by several members of the party. Additionally, his skill in striking a bargain came in very handy at the Shoshone encampment where the expedition acquired much-needed horses.
William Clark was particularly taken with young Jean Baptiste (whom he nicknamed "Pomp"), and by extension the entire Charbonneau family, including Toussaint. Despite having had to reprimand him with regard to his duties (October 27, 1805) and having intervened in a marital dispute in which Charbonneau hit his wife (August 14 of that year), Clark nevertheless offered to set Charbonneau's family up comfortably in St. Louis after the expedition, and to provide an education for Jean Baptiste.
Charbonneau initially declined Clark's offer to relocate to St. Louis, preferring life with the Mandan and Hidatsa. He was paid $503.03 for his nineteen months with the expedition, and remained in the upper Missouri area for some time. However, by 1809, the family had indeed relocated to St. Louis and Charbonneau briefly took up farming for a living. This lifestyle appears to have disagreed with him, and he gave it up after a few months, leaving with Sacagawea and entrusting the care of Jean Baptiste to William Clark, to whom he had sold his 320 acre (1.3 km²) grant for $100.
He then took a job with Manuel Lisa's Missouri Fur Company, and was stationed at Fort Lisa. Evidence suggests that, while Charbonneau was on an expedition with the company in 1812, Sacagawea died at the fort. The following year Charbonneau signed over formal custody of his son Jean Baptiste and his daughter Lisette to William Clark.
During the period of 1811-38 Charbonneau also worked for the Upper Missouri Agency's Indian Bureau (a federal agency) as a translator, making from $300 to $400 per year from the government. It is thought that he owed this position to the patronage of William Clark, who was from 1813 the governor of the Missouri Territory; upon Clark's death, Charbonneau's employment with the government came to an abrupt halt.
Surviving records show that Charbonneau was widely disliked by others in the Missouri Territory. Part of the reason for this may be his casual attitude toward employment: he was variously hired by Lisa's Missouri Fur Company and by John Jacob Astor's American Fur Company, bitter rivals. He is also said to have abandoned another employer, James Kipp, while on a fur expedition in 1834. Perhaps because of this, Charbonneau gained a good deal of his livelihood in work as a guide for people from outside the area, among whom were Karl Bodmer and Maximilian zu Wied-Neuwied; to this end he would play up his experience with Lewis and Clark to its best advantage.
Charbonneau is known to have had altogether five wives, all Native American girls who he married when they were sixteen years old or younger; he may have had more wives that have been lost from the record. His last known wife, an Assiniboine girl, was 14 when she married him in 1837; he would have been more than 70 years old.
He is said to have died at Fort Mandan.
Charbonneau (and his son) appear as important characters in Larry McMurtry's tetralogy The Berrybender Narratives.
Note: dates and locations of Charbonneau's birth and death are taken from information at the Programme de recherche en démographie historique at the Université de Montréal and are not necessarily authoritative. Other research places his date of birth in 1758, which would have made him 46 at the time of the Lewis and Clark expedition.