“It feels heartbreaking,” Rosanne Cash admitted through tears after finding out that an ancestor of her mother, Vivian Liberto Cash — who was famous for being the first wife of singer-songwriter Johnny Cash — was enslaved. This ancestor was Vivian’s maternal great-great grandmother, a Black woman named Sarah Shields, whom Rosanne learned about for the first time ever during an episode of the PBS show Finding Your Roots that aired in Feb.