|Pierre Chouteau, Jr., was born in 1789 in Saint Louis. He traded along the Mississippi River as a teenager. He joined the American Fur Company in 1827. Soon he began using steamboats to trade along the Missouri River. He built Fort Pierre Chouteau just outside of the current city of Fort Pierre. The city took its name from the fort. In a few years, the American Fur Company became Pierre Chouteau, Jr., & Company.