Trade, art, and ideas linked Emerald Mound, both physically and spiritually, with mound sites throughout the eastern half of North America.Mound building, as a practice, was widespread. Over thousands of years, the native peoples who built mounds in North America also maintained networks of trade along trails like the Natchez Trace. Trade in raw materials and particularly in fine ceremonial objects was brisk. Artists bartered for items made from shell, copper, feathers, and clay. The symbolic images worn by the elite - winged serpents, panthers, and birds, for example - showed up at sites hundreds of miles apart. Photo CaptionsMonks Mound Monks mound is the largest earthwork in the US built before Europeans arrived. It is part of the Cahokia complex of 120 mounds on 3800 acres.EtowahThese mounds are part of the most intact Mississippian cultural site in the southeastern US.MoundvilleWith 29 mounds covering 185 acres, Moundville was one of the most important sites in the southeastern US.