This hammered copper artifact depicts an Indigenous person wearing a bird costume and holding a severed head and a mace. (Image credit: Smithsonian National Museum of Natural History (CC0))QUICK FACTSName: "Birdman" copper plateWhat it is: A copper plate with a hammered decorationWhere it is from: Cahokia Mounds, IllinoisWhen it was made: 13th centuryThis copper plate was discovered in the late 19th century in a prehistoric Native American burial at the Etowah Indian Mounds archaeological site in Georgia, but it was likely made hundreds of miles away at Cahokia Mounds in Illinois. While the decorative plate showcases long-distance trade and a shared ritual culture among early Indigenous grou...