Other extraordinary moments have followed. In 2015, on another anniversary, she found herself on the steps of the Alabama Capitol, holding hands this time with Bernice King. It was easy, again, to get lost in the past, and she reflected on the day in 1963, when Bernice’s father, Martin Luther King, had offered his olive branch to the nation. He had proclaimed what seemed more like a fantasy than a dream: “One day down in Alabama … little black boys and little black girls will be able to join hands with little white boys and little white girls as sisters and brothers.” A half-century later, Peggy was standing in solidarity with Bernice.

“We hugged each other,” Peggy remembers, “and I told her I loved her. She said she loved me, too. And we do.”

Later, she writes, “I could not help but wonder how the course of history might have been different if Martin Luther King and Daddy had known that one day, right down here in Alabama, that little black girl and little white girl holding hands would be their own daughters.”

All of this has given her a sense of purpose, and as an advocate for peace and social justice, she has raised her voice in multiple settings – at universities and churches and civil-rights celebrations, and sometimes before delegations from Congress. Doug Tanner, a Methodist minister and founding director of the Faith and Politics Institute in Washington, D.C., has been the architect of some of those appearances.

"I've seen her move Congressional audiences to tears," he says, “and as a writer, she has opened a window onto tragedy and shame – and in a profoundly personal way, the possibility of redemption."

But redemption, inevitably, is haunted by the past, and she has seen the through-line from the worst of Wallace to the presidency of Donald Trump. She knows the dread many feel – a fear that maybe the last 50 years have produced a perfect storm of division from which it will be hard for the country to heal. And on the issue she cares about most, the racial justice her father once opposed, she has seen the threat to hard-earned progress. Still, she holds on to hope. She believes it is possible for decency to triumph. She has seen it before. This is the lesson she learned with her father, even as she understood what it cost.