As construction of the Smithsonian’s National Museum of African American History and Culture progresses toward its September opening, Museum Director Lonnie Bunch joined CBS “60 Minutes”’ Scott Pelley on a visit to Mozambique in search of a ship that carried hundreds of African slaves to the bottom of the Indian Ocean when it foundered 220 years ago. “The story of slavery is everybody's story,” Bunch explained to Pelley. “It is the story about how we're all shaped by, regardless of race, regardless of how long we've been in this country. We hope that we can be a factor to both...