Bette Greene, a critically acclaimed young-adult novelist who confronted anti-Semitism, domestic violence and homophobia in books such as “Summer of My German Soldier” and “The Drowning of Stephan Jones,” which were frequently targeted in book-banning crusades during the culture wars of the 1990s, died Oct. 2 in Lakewood Ranch, Fla. She was 86.

The cause was congestive heart failure, said her son, Jordan Greene.

Ms. Greene often joked that she had been a professional writer since age 9, when she wrote a newspaper story about a barn fire in her tiny Arkansas town for 18 cents. Decades later, she published a debut novel that sold more than a quarter-million copies in its first paperback printing and was adapted into an Emmy-winning TV movie, despite being rejected by more than a dozen publishers.

Published by Dial Press in 1973, “Summer of My German Soldier” told the story of Patty Bergen, a Jewish girl in 1940s Arkansas who is beaten by her father, ignored by her mother and finds love and support from the family’s Black housekeeper, Ruth, and from a German prisoner of war, Anton, who escapes from a nearby military camp.

The book ended tragically, with Patty labeled a “Jew Nazi-lover” and sent to a state reformatory for secretly feeding and hiding Anton, who hates Nazis and teaches her that she is “a person of value.”

“This is an exceptionally fine novel about a young girl whose mediocre parents don’t like her, precisely because she is an inconveniently exceptional human being,” literary scholar Peter Sourian wrote in a New York Times review.

While some critics questioned whether the novel’s brutal scenes of domestic violence were appropriate for younger readers, “Summer of My German Soldier” became a National Book Award finalist and was adapted into a 1978 television movie, co-written by Ms. Greene and featuring Esther Rolle, who earned an Emmy Award as Ruth.

Ms. Greene had grown up as one of the only Jewish children in her town, just like her fictional protagonist, at a time when nearly 23,000 captured Axis troops were being sent to Arkansas POW camps. Asked whether her novel was autobiographical, she once responded by referring a reporter to the dust jacket, which simply described the story. In other interviews, she acknowledged that she, too, had a Black housekeeper named Ruth.

Her son said that Ms. Greene never went further in explaining the inspiration behind Patty Bergen. But in a short video interview in 2011, Ms. Greene seemed to declare that the entire novel was autobiographical, and that she had actually been punished for helping a German POW as a young girl.

“It’s about my life,” she said. “I spent 40 years denying it was about my life. But it was a story that was bursting out to be told. . . . Before, I had felt that I had harmed a lot of people. I was ashamed. It took me a lot of years to be able to say, ‘I think I did the right thing.’ Now I’m sure I did the right thing.”

“I wrote truth, that’s all I did,” she added. “So now I’m free.”

Ms. Greene wrote six more novels, including “Philip Hall Likes Me, I Reckon Maybe” (1974), which received a Newbery Honor as one of the country’s best children’s books and was followed by two lighthearted sequels. She returned to darker subject matter in novels such as “The Drowning of Stephan Jones” (1991), one of the first young-adult novels to address violence against gay people.

Narrated by an Arkansas teenager named Carla, the novel examined the actions of a boy she has a crush on, who carries “his very own leather-bound Bible” and is part of a group of young men who harass a newly arrived gay man in their small town, ultimately throwing him off a bridge. Ms. Greene called the novel “not so much a whodunnit as a whydunnit,” inspired by a similar 1984 murder in Bangor, Maine.

“I looked at a picture of the three young men who were arraigned,” she later told the Boston Globe. “They were 16, 17 and 18. They didn’t look like criminals. One looked like my son. Looking at that picture, I started wondering — where does hate come from? Some of it comes from booze and boredom. But the people I interviewed always came back to one source — the church.”

Ms. Greene spent nearly two years researching the book, interviewing more than 400 people. In an “author’s affidavit” from a 2012 edition of the novel, she recalled that she was attacked during one interview with a Christian religious leader, who slammed her against a wall, pressed his hands against her throat and lifted her off the floor, insisting that she never write her planned novel.

While most critics concluded that “The Drowning of Stephan Jones” was less artistically accomplished than Ms. Greene’s earlier books, the novel was nominated for a Lambda Literary Award, for LGBTQ fiction, and taught in schools, much like “Summer of My German Soldier.”

Both books were also occasionally banned and included in an American Library Association report of the “100 most frequently challenged books” of the 1990s. School districts barred them from classrooms amid complaints about their “objectionable language,” depictions of racism, violence and sexuality, and alleged promotion of “anti-Christian beliefs,” according to the ALA and the National Coalition Against Censorship.

Ms. Greene was unbowed. She said she received numerous letters from readers who thanked her for opening their eyes to the problem of anti-gay violence and noted that she was far from the only author to face opposition from conservative parents and skeptical school boards.

“You don’t have to feel sorry for me,” she wrote in a Boston Herald essay after the ALA report was released, “because I’m in the company of Shakespeare, Steinbeck, Twain and even [Maurice] Sendak’s classic picture book, ‘In the Night Kitchen.’ ”

Ms. Greene was born Bette Jean Evensky in Memphis on June 28, 1934, and grew up in nearby Parkin, Ark., where her parents ran a general store. She later said that she considered herself “the unluckiest, unhappiest girl in town,” given her family’s Jewish faith in the middle of the Bible Belt. For a few years, she became a born-again Christian.

“I used to sneak into the tents of itinerant Protestant preachers the way a teenager today might sneak into an X-rated movie,” she said. “And as the evangelist spoke with easy familiarity of the fires of Hell, I could feel its heat. So I ‘caught’ religion as simply as others caught colds.”

Ms. Greene graduated from high school in Memphis, wrote for publications including the Memphis Commercial Appeal and attended several colleges, spending a year in a Paris educational program that she later drew on for “Morning Is a Long Time Coming” (1978), a sequel to “Summer of My German Soldier.”

She ultimately studied astronomy and writing at Columbia University but left without receiving a degree and worked as a public information officer for the Red Cross before marrying Donald Greene, a neurologist, in 1959. They settled in Brookline, Mass., where Ms. Greene began writing “Summer of My German Soldier” after the birth of her daughter.

Her husband died in 2008. Survivors include her two children, Jordan Greene of Bel Air, Md., and Carla Greene of Newton, Mass.; a sister; and four grandchildren.

Ms. Greene’s later novels included “Them That Glitter and Them That Don’t” (1983), about a lonely teenager who dreams of leaving home to become a country and western singer. She was working on a nonfiction book about bullying at the time of her death.

“I think I identify with the underdog,” she said in a 2011 interview. “I’m skeptical of people who have easy answers for things. You don’t have to accept other people’s bullying, because once you accept it, it’s never-ending.”