Toussaint Charbonneau was a French Canadian explorer, fur trapper, guide, and trader. He is famous for helping Lewis and Clarke on their expedition. 

In November 1804, Lewis and Clarke stopped at North Dakota to build a fort on the Missouri River to wait out the winter before continuing their expedition. 

At Fort Mandan Lewis and Clarke met Charbonneau who was recently married to Sacagawea who was Shoshone. They needed a new guide and translator to help them safely cross through Indian territory.

On November 4 1804 Charbonneau was recruited to the Corps of Discovery. He moved into Fort Mandan with Sacagawea and in 1805 their son, Jean Baptiste, was born.