CHICAGO – The Chicago teachers' strike ended Thursday afternoon with the mayor and the union president agreeing on one last detail: Teachers and students will make up five of the 11 days lost to the historic strike.

Students in the nation's third-largest school district will return to class Friday.

The strike had idled academics, sports and college prep for about 350,000 students and their families. As it wore on, students missed lessons, state playoff tournaments and an ACT exam date. The gap in instructional time approached the amount experts point to as detrimental to kids' learning.

Still, parts of the deal could be seen as the latest victory in a wave of labor action by teachers. Since early 2018, teachers have taken charge of education policy debates, marching in the streets and filling state capitols to push for changes in how states educate kids and pay their teachers.

The Chicago strike was longer than nearly every teacher walkout since 2018.

"I’m glad we get to return to work," said union President Jesse Sharkey on Thursday afternoon. "Frankly, it’s been hard on teachers, on parents, on kids."

Negotiations came to a dramatic head Wednesday night at a raucous, hours-long meeting of the 700-member governing body of Chicago Teachers Union. Delegates voted by about a 60-40 percent majority to accept a tentative agreement with City Hall but to continue striking Thursday until the mayor agreed to make up lost instructional time – essentially, as the mayor put it, paying them for the days they were striking.

Teachers had gone without pay during the strike, and Lightfoot had been firm about not wanting to extend the school year or cut into scheduled breaks. But by Thursday, she said it was in the interest of everyone to get back to class.

"In the spirit of compromise, we agreed," she said. "It was a hard-fought discussion, but I think this was the right thing to do for our city.”

Now that the teachers union has voted to accept the tentative agreement with City Hall, the union's more than 25,000 members will vote on the contract.

Separately, the Service Employees International Union Local 73 – which represents school staff workers such as bus aides, custodians, security officers and special education classroom assistants – announced Wednesday it had voted to ratify its new contract. The union went on strike with teachers on Oct. 17 to demand higher pay for its members, who are among the lowest-paid workers at CPS.

What concessions did teachers win?

Sharkey said Wednesday that while the tentative agreement has not met all CTU demands, it addresses many of the union's largest concerns, such as limiting class sizes and hiring more support staff.

“We believe that this is an agreement which will produce real, lasting benefits in our schools. It’s a contract that we can believe in," Sharkey said.

In addition to guaranteeing all CTU members a 16% raise over the life of the five-year contract, the offer invests $35 million in reducing class sizes – up $10 million from the city's previous offer.

On staffing, the city's offer guarantees that every school will have a nurse and social worker by 2023. The offer includes 120 new "equity positions" for highest-need schools – such as counselors, restorative justice coordinators and librarians – and additional staffing in bilingual and special education.

"CTU won some important things in the contract," said Celeste Ramovic, a Spanish teacher at Lane Tech on the city's North Side. "But it’s also really disappointing that we had to go on strike for two and a half weeks to get things that should be really basic – things that, in the suburbs, you don’t have to bat an eye and it’s given to you."

The teachers did not win a 30-minute morning prep period for elementary school teachers, something union leaders had stayed on strike to try to gain. The demand seemed to snarl already tense talks. Lightfoot said she wasn't giving up more instructional time for that.

Strike attracted presidential candidates

The strike began Oct. 17, after months of negotiations between City Hall and two unions fell through.

Teachers garnered a wave of support — from Democratic hopefuls Bernie Sanders and Elizabeth Warren to the Windy City's own Chance the Rapper, who hosted "Saturday Night Live" while wearing red and praising teachers during his opening monologue.

Teachers initially said they walked out because Lightfoot's office had not met their demands on limiting class sizes and hiring more support staff. The Chicago Teachers Union wanted all of that in writing in its contract, not in the verbal commitments teachers had received from the district.

Teachers also wanted the district to address access to affordable housing in the city, as more than 17,000 CPS students are currently homeless, according to CTU.

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As the strike wore on, the union said it wanted more concessions from the city, especially related to teachers' prep time.

Lightfoot accused the union of "moving the goalposts." After a tentative deal was reached, the union wanted a return-to-work agreement that would have allowed teachers to make up all the days lost to the strike – something they said was common in past agreements to end strikes.

How did parents cope during the strike?

Classes were canceled during the strike, but school buildings remained open and meals were served.

Parents expressed frustration about kids' long interruption from classroom learning, which they said also upended their kids' college applications, sports playoffs and more. CPS student-athletes whose state tournaments continued or started during the strike were not allowed to participate.

Life without access to CPS' special education resources was challenging for Shani Blackwell, a single mom who lives with her 8-year-old son on the city's West Side.

"My autistic son's anxiety is increasing," Blackwell said. "I want teachers to have what they need to do their jobs well. I blame the city and the district."

For Scott Walter's 16-year-old daughter, who is in the throes of the college application process, the strike "made an already stressful situation much worse."

Walter said Thursday that he was happy his daughter would be going back to school, but that he was concerned the strike could have lasting, negative effects on parent donations to schools and the future of the city's relationship with the Lightfoot administration.

Education coverage at USA TODAY is made possible in part by a grant from the Bill & Melinda Gates Foundation. The Gates Foundation does not provide editorial input.