Over the last two years, Mr. Reynolds and Mr. Kiely have visited more than 100 schools around the country, speaking to some 40,000 students about the book. Mr. Reynolds said they occasionally encountered resistance from nervous school administrators. Scheduled talks at a school in Newark and a young-adult literary festival in Texas were canceled over concerns about the politically charged topic, Mr. Reynolds said.

The overwhelmingly positive reception to “The Hate U Give” has stunned Ms. Thomas, 29, a former teenage rapper who worked as a church receptionist in Jackson while finishing her novel. “I knew that while the topic was timely, it was also controversial,” she said.

“I say, ‘It probably will make you uncomfortable,’” she said. “I’m not here to give you comfort.’”

As a bookworm growing up in a poor neighborhood in Jackson, Ms. Thomas didn’t have many literary role models. She tore through the Harry Potter books and other series at the library after school, but characters whose lives felt familiar to her were scarce.

“For me, hip-hop was a mirror when young-adult books were not,” she said. “I could see myself in a Nas song more than I could see myself in a book.”

In her first year at Belhaven University, she took a creative writing class, and felt out of place as the only black student in the classroom. One day, her professor asked students to talk about their travels over the summer. Ms. Thomas, who was raised by her single mother and grandmother, had never left Mississippi. When she got to her car in the parking lot, she cried.

But her professor encouraged her to draw on her own experience in her writing. “He told me that my stories, and the stories of people in my community, mattered,” she said. When she turned in the story about Starr, the narrator of “The Hate U Give,” he told her that she could turn it into a novel.

“The Hate U Give” takes place in a neighborhood modeled on the community Ms. Thomas grew up in, where drugs and gang violence were inescapable but people looked out for one another. Starr shares many of the author’s traits — she loves basketball and Tupac, and shuttles between two worlds: her affluent, mostly white private school and her impoverished neighborhood.