A crowd that included a Georgia Supreme Court justice, an assistant attorney general, a superior court judge and a former governor gathered in the sunshine and 92-degree heat Wednesday to commemorate a plaque at the Atlanta History Center.

It wasn’t so much the simple black-and-white sign that brought them there but the memory of John Marshall Slaton, the lawyer-governor who sacrificed his political career 100 years ago to grant clemency to Leo Frank, widely believed to be wrongly convicted of murder because of anti-Semitism. Slaton commuted Frank’s death sentence to life in prison. But that wasn’t the end of the story.