One afternoon earlier this year, Wendell Yellow Bull received a call from a longtime friend with word of a troubling discovery. Objects from one of the most notorious massacres of Native Americans in U.S. history were in the collections of the American Museum of Natural History, his friend said. Some of them appeared to be children’s toys, including a saddle and a doll shirt. Memories of what Yellow Bull had been told about the incident throughout his life came rushing back. Yellow Bull is a descendant of Joseph Horn Cloud, who survived the 1890 massacre at Wounded Knee.