While most Americans know Native American tribes like the Lakota or Cherokee, the Mandan are less well known. In her Pulitzer Prize-winning book Encounters at the Heart of the World, historian Elizabeth Fenn recounts the story of the Plains Mandan tribe as they rose to a population of 12,000, before being nearly wiped out in a few short years. Fenn turns to untraditional sources from archeology to climatology to tell a history that supposedly couldn’t be written.

Later in the show: It’s been a year since the mass shooting of churchgoers in Charleston, South Carolina by a gunman whose online manifesto includes photos of himself with emblems of white supremacy. The shooting sparked national conversation about the removal of Confederate battle flags and monuments from public spaces. In a candid conversation, Chioke I’Anson and Kelley Libby share their thoughts on Richmond, Virginia’s Confederate monuments, racism, and growing up in the Deep South.