A White Southerner Runs The Only Museum Solely Memorializing Slavery

America needs more symbols memorializing slavery and John Cummings, a white southerner, has helped to make that happen.   He's opened a museum at the Whitney Plantation, the first and only museum in the country dedicated solely to slavery.  The Atlantic spoke with Cummings and produced a short video about his involvement with the museum and the stories it highlights.  “This isn’t black history we’re talking about, this is our national history. It's my history, it's your history,” Cum...