Complex sentence: Chouteau was a member of Bernard Pratte and Company which was the Western agent for the American Fur Company in 1827 and pioneered the use of steamboats on the Missouri River.
Split into simpler sentences: Chouteau was a member of Bernard Pratte and Company, which was the Western agent for the American Fur Company in 1827. He pioneered the use of steamboats on the Missouri River.