“Burlington is generally a pretty safe city,” Melby said. “People were concerned about that sort of stuff coming to the area.”

As people spoke for and against Statz’s lesson on Facebook, residents of the Southeastern Wisconsin town felt like the dividing lines had been drawn.

A heated school board meeting

The showdown came at a Sep. 14 school board meeting.

Around 200 community members packed into the bleachers of a gymnasium and spent two hours speaking for and against the lesson plan. Some defended Statz for creating an environment in which her students feel free to ask difficult questions. Others called on the school board to fire her, saying she had pushed an agenda on fourth graders and violated district policy.

At the end of the meeting, a board member read a short statement to the audience, acknowledging “this is a highly charged and emotional topic.” Then, without using Statz’s name, the board said that she wasn’t going to be fired over the “one-time use of curricular materials.” The issue was a “personnel matter” and was addressed internally, the board said. (Statz said her principal and the superintendent had a conversation with her after complaints surfaced, but that she was not disciplined.)

A man in a Trump shirt criticizes the Black Lives Matter movement at a Sept. 14 school board meeting in Burlington, Wis.Mike Ramczyk via SLN Racine County

Many people left the meeting disappointed. Those who wanted Statz fired believed the school board was yielding to Black Lives Matter protesters. Statz’s defenders said the board should have more clearly defended her and lessons tackling racism.

“Our nation is still divided by issues of race but the impression being communicated to our students that we can’t talk about it is toxic in my mind,” said Nicole Fish, 27, a white teacher who lives in Burlington and works in Kenosha. “Burlington is a microcosm of things happening in the Midwest in general, and our country at large.”

"Burlington is a microcosm of things happening in the Midwest."

Nicole Fish, Burlington resident

No one from the school board or district would agree to an interview. Thomas, the district’s communication coordinator, said the administration wanted to “focus attention on solving the problem” rather than perpetuating the debate and stirring up “mixed emotions in the community.”

“What we’re experiencing in the Burlington community represents what is being experienced in communities across America,” Thomas said. “There are many sides and perspectives to understand and it takes time and dedication to seek community-wide reconciliation. The Burlington Area School District is committed to that process.”

'There is no neutrality when pursuing equity'

The school board meeting did little to calm emotions in the town. Statz, Garbade and other members of the Burlington Coalition for Dismantling Racism said they faced more harassment online.

“You’ve started this s--- in my city… mostly everyone will fight you,” one woman told Garbade on Facebook. Screenshots of several messages sent to Statz show men called her a “piece of human garbage” and a “piss poor excuse of a teacher”; one told her, “You brought this on yourself,” while also commenting on her “nice little family.”

The backlash continued offline as well. Statz said friends stopped inviting her to neighborhood get-togethers. Ketelsen said some people stopped attending her husband’s church.

“I feel like for the most part, people have made their minds up about racism and equity and those kinds of things long before this stuff even started coming out and being exposed,” Garbade said. “So it’s very hard to have conversations.”

Then, three days after the school board meeting, according to the district, a group of students etched “die [n-word] die” and “down with BLM” into wood chips at Cooper Elementary School, where Statz teaches.

Cooper Elementary School in Burlington, Wis.Darren Hauck / for NBC News

The following day, Sept. 18, Superintendent Plank issued an open letter in response. He apologized for the district previously declaring neutrality on the Black Lives Matter lesson plan.

“I see how my perspective was offensive and understand that there is no neutrality when pursuing equity,” Plank said in the letter. “The fact that we even need to specifically say that Black Lives Matter to affirm the importance of human beings is to say that we as a nation have not done a good job of regarding Black and brown people as valuable members of our society historically or currently.”

He acknowledged the district received “a wave of polarized feedback, some of it espousing racist, hateful, and threatening sentiments,” and said the attacks against school staff and community members must stop.

Two weeks later, a group of minors spray painted the n-word on the floor of another school that was under construction.

Burlington police would not release reports on the incidents, citing confidentiality for cases that are ongoing and involve juveniles, but told NBC News that the vandals stated what they did was “dumb” and “stupid.”

Even before the vandalism, Garbade decided to pull her children out of Burlington schools and enroll them in Kenosha’s district. “Looking at the recent hate crimes in Burlington,” she said, “it seems like it was a very wise choice.” However, she plans to continue pushing the Burlington district to adopt an anti-racism policy, expand the curriculum to include Black history lessons and address racial disparities in discipline.

“I realized that somebody needed to bring awareness to Burlington and what was happening here, and to challenge the people of Burlington to rise up and be better,” Garbade said.

The hate mail to Statz has recently slowed. She felt things calmed down once the school administration issued more forceful public statements supporting her and denouncing racism.

Statz hasn’t taught another lesson about the Black Lives Matter protests, though she doesn’t think she did anything wrong. Next time, she thinks she would send an email to parents in advance of a lesson to get ahead of what circulated on social media.

Over the past two months, there were moments she felt overwhelmed, but she said there’s one thing that friends from Chicago have reminded her that made this experience easier.

“If I was teaching this in Chicago, it wouldn’t be making the same impact as it does here,” she said.