Fort Ancient culture flourished from c.1000 to c.1750 CE among a people who predominantly inhabited lands on both sides of the Ohio River in areas of present-day southern Ohio, northern Kentucky and western West Virginia. Like the Mississippian culture peoples of this period, they built earthwork mounds as part of their expression of their religious and political structure. Fort Ancient culture was once thought to have been a regional extension of the Mississippian culture. But, scholars now believe that Fort Ancient culture developed independently and was descended from the Hopewell culture (100 BCE—500 CE). The people in those earlier centuries also built mounds as part of their social, political and religious system. Among their monuments were earthwork effigy mounds, such as Serpent Mound in present-day Ohio.