Together they had four children:[3][unreliable source] Shortly after Pélagie's death, the widower Chouteau married Brigitte Saucier on 17 February 1794, in St. Louis.

For a long time, they held monopoly rights on the lucrative fur trade with the Osage, and they expanded their St. Louis businesses to many parts of the emerging economy.

In 1796, he established a trading post in the western part of their territory, at the junction of the Neosho River and Saline Creek, which became the first permanent European (white) settlement at present-day Salina, Oklahoma.

[7] On July 14, 1804, President Thomas Jefferson named Chouteau the US Agent for Indian affairs west of the Mississippi River.

This was a major step for Chouteau to gain access to officials of the new American federal government, but he also delivered on his responsibilities.

After being appointed a United States agent of Indian Affairs, Chouteau founded the Missouri Fur Company in St. Louis in 1804, together with Manuel Lisa, a Spanish trader from New Orleans.

He became very wealthy and influential in St. Louis, and managed to retain considerable political power after the United States' Louisiana Purchase.

Scypion's children asserted that as their maternal grandmother was Natchez Indian, their mother should have been freed in 1769, and they should have been considered free at birth, by the principle of partus.

The jury decided unanimously in favor of Marguerite and the other Scypion descendants, a decision that withstood appeals up to the US Supreme Court in 1838.