In this conversation first recorded for Washington Post Live on April 27, Yale University professor Ned Blackhawk discusses his new book, “The Rediscovery of America: Natives Peoples and the Unmaking of U.S. History,” which explores the foundational role Native Americans have played in U.S. history, including in the formulation of our country’s Constitution, and how their presence and contributions are frequently overlooked, or worse, erased.