Complex sentence: In 1828, Lucien Fontenelle purchased the former Pilcher's Post, becoming the agent at what became known as Fontenelle's Post, where he represented the American Fur Company on the Missouri River in later Bellevue, Sarpy County, Nebraska.
Split into simpler sentences: In 1828, Lucien Fontenelle purchased the former Pilcher's Post, becoming the agent at what became known as Fontenelle's Post. He represented the American Fur Company on the Missouri River in what developed as Bellevue, Sarpy County, Nebraska.