When the mother of a Black ninth grader at a private school in Charlotte, N.C., learned last month that his English class was going to be studying August Wilson’s “Fences,” an acclaimed play examining racism in 1950s America, she complained to the school.

The drama, which won a Pulitzer Prize in 1987 and was adapted into a critically praised film starring Denzel Washington in 2016, is about a Black family and is peppered with racial slurs from the first page.

Faith Fox, a lawyer and single mother, said in an interview that she imagined her son’s mostly white class at the Providence Day School reading the dialogue out loud. She said her main concern was that the themes were too mature for the group and would foster stereotypes about Black families.

After a round of emails and a meeting with Ms. Fox, the school agreed to an alternate lesson for her son, Jamel, 14. The school also discussed complaints with the parents of four other students. Ms. Fox’s disagreement escalated. She took it to a parents’ Facebook group, and later fired off an email that school officials said was a personal attack on a faculty member.

On the day after Thanksgiving, the school notified Ms. Fox that Jamel would no longer be attending the school, the only one he had ever known.

His mother called it an expulsion. The school referred to it as “a termination of enrollment” that had to do with the parent, not the student. Either way, what was meant to be a literary lesson in diversity and inclusion had somehow cost a Black 14-year-old his place in an elite private high school.

Jamel had recently made the school basketball team and said in an interview that he hoped to graduate as a Providence Day lifer. “I was completely crushed,” he said. “There was no, ‘Please don’t kick me out, I won’t say this, I won’t say that, my mom won’t say this, my mom won’t say that.’” He is making plans to attend public school in January.

This year has brought a reckoning with race at many American institutions, including schools. When widespread street protests erupted after the death of George Floyd at the hands of Minneapolis police officers, young people across the country used social media to expose racism at their schools. At Providence Day School, Black students shared stories of discrimination and insensitivity on Instagram, and the school was among many that released statements against racism.

“For the Black members of our community, we see you, we hear you and we will act,” the statement said. The school also revised its bias complaint process and created alumni, faculty and student diversity groups.

But Ms. Fox said, she felt the school’s treatment of her son proved this was all just lip service.

“You can have the important conversations about race and segregation without destroying the confidence and self-esteem of your Black students and the Black population,” Ms. Fox said in an interview. Just over 7 percent of the school’s 1,780 students are Black, about 70 percent are white, and the rest identify as members of other minority groups.

A spokeswoman for the school, Leigh Dyer, said last week that officials were “saddened” that Jamel had to leave.

“As a school community, we value a diversity of thought and teach students to engage in civil discourse around topics that they might not necessarily agree on,” Ms. Dyer said. “We have the same expectation for the adults in our community.”

The Nov. 27 termination letter cited “bullying, harassment and racially discriminatory actions” and “slanderous accusations towards the school itself” by Jamel’s mother.

Ms. Dyer provided a statement that said Ms. Fox had made “multiple personal attacks against a person of color in our school administration, causing that person to feel bullied, harassed and unsafe” in the discussions about “Fences.” It also said Ms. Fox had a history of making “toxic” statements about the faculty and others at the school, but did not provide examples.

Ms. Fox denied this. “Instead of addressing the issue they’re trying to make me seem like an angry, ranting Black woman,” she said.

The New York Times reviewed emails and Facebook messages that Ms. Fox provided and also interviewed two other Providence Day parents who said they had similar concerns about the play and about a video the school used to facilitate conversations about the racial slur. They spoke on condition of anonymity to protect their children.

The school had notified parents in early November about the lesson plan in an email. Noting the frequent appearance of the slur in dialogue, it said that students would say “N-word” instead when reading aloud. It said time would be “devoted to considering the word itself and some of its more nuanced aspects of meaning.”

The email included a link to a PBS NewsHour interview with Randall Kennedy, a Black professor at Harvard, discussing the history of the slur while using it repeatedly.

“It wasn’t something that I thought was appropriate for a roomful of elite, affluent white children,” Ms. Fox said.

Her son was also dreading the lesson, which he would have attended via video because of the coronavirus pandemic. “It’s really awkward being in a classroom of majority white students when those words come up,” Jamel said, “because they just look at you and laugh at you, talk about you as soon as you leave class. I can’t really do anything because I’m usually the only Black person there.”

Ms. Dyer, the spokeswoman, said the school had introduced the study of “Fences” in 2017 in response to Black parents who wanted more lessons addressing race. In past years, there had been only one complaint about the play, she said.

After her son was offered an alternative assignment, Ms. Fox posted about “Fences” to the Facebook group. Other parents said they too had concerns about the play and the PBS video. One comment directed her to an online essay by a student from a prior year who described the “dagger” she felt “cutting deeper and deeper” with each mention of the slur in the video.

That’s when Ms. Fox sent an email to the school’s director of equity and inclusion, calling her a “disgrace to the Black community.” Ten days later, Jamel was kicked out of the school. Ms. Fox said that she was surprised but that she does not regret sending the email in the heat of the moment.

After Jamel’s expulsion, a letter signed by “concerned Black faculty members” was sent to parents of the four other students who had complained, arguing the literary merits of “Fences.” It said great African-American writers do not create perfect Black characters when they are trying to show the “damaging legacy of racism.”

That is a view held by many critics and academics. Sandra G. Shannon, a professor of African-American literature at Howard University and founder of the August Wilson Society, said schools should not shy away from the “harsh realities of the past.”

Katie Rieser, a professor at Harvard Graduate School of Education, said “Fences” is taught widely in middle school and high school, but she also urged that it be done so with care.

“It’s telling a story about a Black family that, if it’s the only text or it’s one of only a few texts about Black people that students read, might give white students in particular a sense that Black families are all like this Black family,” she said.

Ms. Fox said the fight to be heard as a Black parent at a predominantly white private institution had been “exhausting.”

She recalled when Jamel came home upset in elementary school after a field trip to a former slave plantation. After she complained, the school ended the annual trips, she said.

The other day, she said her son told her he finally understood “why Black Lives Matter is so important and is not just about George Floyd and all of these people dying in the streets, but it also has to do with how we’re treated everywhere else.”