sentences:  The area known as St, Charles was within the territory of the Middle Mississippian culture during the Woodland Period of Native American History.In early modern times, possibly after Hernando De Soto's initial exploration of the American Southeast, the area encompassing the whole of Arkansas County and much of Eastern Arkansas became Quapaw territory and remained so until the arrival of French explorers in the 17th Century.After American settlers started to move into the Arkansas territory, A treaty signed in 1818 moved most all of the Quapaw from what is now Arkansas County to the center of the state.