After playing Scout in the movie of “To Kill a Mockingbird,” in 1962, Mary Badham endured a rude homecoming when she returned to Birmingham, Alabama. Having just spent six months in California with her mother, living in a racially integrated apartment complex, she found herself suddenly an outsider back home. “The attitude was ‘Lord knows what she might’ve learned out there!’ ” Badham recalled the other day. “Some families, I’d been welcome in their homes, and after the film, I was no longer welcome.”

Like the adult Scout in Harper Lee’s newly published “Go Set a Watchman,” Badham left the South during the era of segregation, and returned to find that people she once considered unequivocally good in fact bore the markings of that evil system. In the case of Scout, as revealed with alarm by reviewers of “Watchman,” it’s her sainted father, Atticus, who emerges as an overt racist, inveighing against threats to segregation from the U.S. Supreme Court and local lawyers for the N.A.A.C.P. Badham similarly discovered a mean streak in family friends who didn’t tolerate her breaking of Southern white taboos. “I was ostracized and it was painful,” said the adult Badham.

This past Tuesday night, nine hundred people, a sellout crowd, came to hear Badham read from “Go Set a Watchman” and “To Kill a Mockingbird” at the 92nd Street Y. Harper Lee herself made New York City—specifically the Upper East Side neighborhood around the Y—her second home for more than fifty years. These were her fans, and they clearly had come looking for something to celebrate. When Badham was introduced, they whooped and cheered.

Badham, who was nine when she played the iconic six-year-old and is now sixty-two, was completely overcome. Today a furniture-restorer in rural Virginia, she clasped her hands, raised them in celebration, then took a bow, and finally laughed until she almost cried. She read a brief excerpt from “Mockingbird,” and the first chapter of “Watchman.” Her voice is slow and lilting, quintessentially Southern. Alternately funny and poignant, Badham’s channelling of Jean Louise Finch—in “Watchman,” she has mostly shed her famous nickname—elicited frequent laughter.

In the Q. & A. that followed, moderator Mary Murphy, the director of the documentary “Harper Lee: From Mockingbird to Watchman,” asked Badham if she was surprised by the evolution of Atticus. She was not. In the Alabama she knew, it was not unheard of for a white man like him to righteously defend a black man like Tom Robinson against an unjustified charge of rape, and at the same time believe, as Atticus says in “Watchman,” that black people were “backward,” not “ready” to exercise their full civil rights. She heard all that and much more growing up in Birmingham. We all did.

PHOTOGRAPH BY NANCY CRAMPTON / 92ND STREET Y

Mary Badham and I were in the same Camp Fire Girls group in 1962. Our group leader had a daughter at Mary’s school, and, upon learning of her mistreatment by some former family friends, invited her to join, in the hope of making her feel more welcome in her home town. Another member of our group was Diane McWhorter, who now is the Pulitzer Prize-winning author of “Carry Me Home,” a history of the civil-rights movement in Birmingham, with a running side story about her suspicions that her own father belonged to the Ku Klux Klan.

The three of us met up at Mary’s reading, and afterward we talked for hours about the vexed state of readers who had loved and revered the original Atticus. Along with them, we mourned the loss of an icon, but we were not shocked. In nineteen-sixties Birmingham, as in Scout’s Maycomb, the two Atticuses could coexist, and did. History delivered Southerners of that era into an immoral world where segregation shaped everything. My mother kept a journal of memorable things my brother and I said as young children; in it, she wrote of a family outing to the municipal airport, where we delighted in watching planes take off. I was five years old, and came home with a question unrelated to aviation: “Do colored people taste things differently from white people?” I asked. “Then why do they have different drinking fountains?” My mother appended, “Why indeed?”

What stood out for the Mary, Diane, and me, as we recalled this twisted system, was how few white people challenged it. My own father was one who did. Not coincidentally, he was an outsider. Raised in the Northeast, he had come to Birmingham after the Second World War and joined the faculty at the local medical school, whose hospital was segregated by floors. On the “white floors, ” doctors addressed patients as Mr. and Mrs. On the “black floors,” my father told us, they used made-up names like “Bo” or “Bessie.” He had refused to do this, arguing that the practice was not only disrespectful but also bad medicine. “If you don’t know the history, you don’t know the patient,” he said, and the first thing in the history was the patient’s name. After administrators pressured him to follow the local custom, he resigned, returning later when new leadership arrived.

I heard this story all my life—it happened before I was born—and when I read “To Kill a Mockingbird,” I fell in love with Atticus, in part because his sterling decency reminded me of my father. Shortly after his death, twenty-two years ago, I wrote a letter to Harper Lee, asking if she would grant me an interview for a profile. I told her my father’s story and asked if she would suspend her famous distaste for public exposure in light of this personal connection to the Atticus character. I received a response soon afterward, postmarked Monroeville, Alabama. She wrote that she was so taken with my father’s story that she almost said yes, but she hated interviews and felt compelled to stick with her standard answer of no. At the end of the letter, she made a comment that I’ve never forgotten. She wrote that “To Kill a Mockingbird” is fiction, while my father’s story is true, and she urged me to tell his story instead. She hoped that some day I would write again, to tell her that I’d begun.