center of the region's thriving fur trade, established primarily by French colonists, some also from New Orleans. Polly Lisa lived in the city with their three children while her husband made his long expeditions to various Indian territories on the Upper Missouri River. After founding Fort Lisa about 1813, a post in what is now part of Omaha, Nebraska, Lisa worked to gain alliances with local tribes, such as the Omaha. After being appointed US Indian agent in the area by the governor of the Missouri Territory, in 1814 Lisa married Mitane, a daughter of Big Elk, the principal chief of the Omaha until 1846. Both sides saw it as a strategic alliance. Lisa and Mitane had two children together, Rosalie and Christopher, born in subsequent years after Lisa's expeditions and wintering over at Fort Lisa. "Kinship and ties of affinity proved more than merely useful to the traders. They were both a source of power and a necessity if one was to achieve success in the trade." Only traders were accepted for marriages to high-status women, such as the daughters of chiefs, as the chiefs saw such marriages as a way to increase their own power. As the Omaha had a patrilineal system, the children of Lisa and Mitane were considered "white" as their father was "white". The tribe protected them, but unless such mixed-race children were officially adopted by a man of the tribe, they were not considered Omaha and had no real place in a gens (clan), the basic kinship unit. Polly Chew Lisa died in 1817 in St. Louis while Manuel Lisa was away on an expedition. After his return the following year, on August 5, 1818, Lisa married the widow Mary Hempstead Keeny, a sister of his friend, the attorney Edward Hempstead. As a widow, she had migrated with her parents and siblings from Connecticut to join four brothers already in Missouri. In 1819 Lisa took his new wife Mary with him for his next expedition and winter at Fort Lisa, Nebraska. He tried to gain custody of his children with Mitane. She let him take Rosalie back to St. Louis the next year for education at a Catholic school, but refused to let him have Christopher. Lisa included provisions for both Rosalie and Christopher in his will, along with his children by his first wife Polly Chew. Only Rosalie Lisa Ely (c. 1815-1904) survived