On August 12, 1806, after some confusion, Lewis and Clark's parties reunited. Now, they embarked on the last leg of the return trip. Now drifting with the Missouri River current, the group traveled this stretch of the journey much more quickly than before. Around August 14, the Lewis and Clark Expedition managed to convince several Hidatsas to join them on their way to Washington, D.C., for an audience with the "Great White Chief," President Thomas Jefferson.
On August 17, the expedition reached Fort Mandan, where Sacajawea and Charbonneau had initially joined the expedition. Sacajawea and her husband now broke away from the expedition, which continued on to St. Louis. Before the couple split off from the group, Captain Clark offered to raise Jean Baptiste ("Pomp"). Sacajawea and Charbonneau considered it, but their son still was not old enough to leave his mother. They told Clark they would consider turning Jean Baptiste over to him in a year, after he had been weaned.
By September, Lewis had recovered from the gunshot wound he received in his men's hunting mishap. At that same time, the expedition finally reached St. Louis. People in the St. Louis area had assumed that everyone on the expedition was dead; when they found out that the explorers had returned—indeed, every single person had survived the two-year trek to California—they rushed out to welcome the battered and exhausted party as returning heroes.
Sacajawea, Charbonneau, and Jean Baptiste stayed in the Fort Mandan area as the expedition headed east. On August 20, Clark wrote the couple a letter from St. Louis. He thanked them both for their help and apologized that he did not have any money to pay Sacajawea for helping so much and enduring so much danger. Clark again offered to raise Jean Baptiste as his own child, and said that if Sacajawea and Charbonneau would bring the boy to St. Louis, he would make sure he got a good education. In the end, Sacajawea and Charbonneau decided to take Clark up on his offer. They took their son to St. Louis, turned him over to Clark, and after a brief stay returned to the wilderness of the Missouri River region.
When Sacajawea and Charbonneau left the expedition at Fort Mandan, Charbonneau received pay for his serivices, despite the countless problems he'd caused along the way. Sacajawea, so reliable and so helpful, received nothing despite the fact that she had saved the entire expedition more than once. Sacajawea had never been officially hired, but was only accompanying Charbonneau, the expedition's "interpreter" (Sacajawea did just as much translating for Lewis and Clark as her husband). Of course, the money paid to Charbonneau did help Sacajawea, as the couple shared joint finances. The pair could have continued on with Lewis and Clark, but Charbonneau felt he was getting too close to civilized country. Always a man of the frontier, Charbonneau preferred to stay in Montana and the Dakotas. Furthermore, now that the expedition was leaving the frontier, Charbonneau knew that his services as interpreter would no longer be needed.
Although he could not pay Sacajawea, Clark felt guilty about not rewarding this woman who had been of such crucial service to the expedition and who had hardly complained while carrying a baby 8,000 miles. Clark's offer to raise and educate Sacajawea's son, Jean Baptiste, shows how great his appreciation of her was. Sacajawea's willingness to consider the offer showed her respect for, and trust in, Clark.