The strike carried political implications, too, raising the risk of a protracted labor battle in President Barack Obama's hometown at the height of the fall campaign, with a prominent Democratic mayor and Obama's former chief of staff squarely in the middle. Emanuel's forceful demands for reform have angered the teachers.
The teachers walked out Sept. 10 after months of tense contract talks that for a time appeared to be headed toward a peaceful resolution.
Emanuel and the union agreed in July on a deal to implement a longer school day with a plan to hire back 477 teachers who had been laid off rather than pay regular teachers more to work longer hours. That raised hopes the contract would be settled before the start of fall classes, but bargaining stalled on other issues.
Emanuel decried the teachers' decision to leave classrooms, calling the walkout unnecessary and a "strike of choice."
Almost from the beginning, the two sides couldn't even agree on whether they were close to a deal. Emanuel said an agreement was within easy reach and could be sealed with school in session. The union insisted that dozens of issues remained unresolved.
Chicago's long history as a union stronghold seemed to work to the teachers' advantage. As they walked the picket lines, they were joined by many of the very people who were most inconvenienced by the work stoppage: parents who had to scramble to find babysitters or a supervised place for children to pass the time.
To win friends, the union representing 25,500 teachers engaged in something of a publicity campaign, telling parents repeatedly about problems with schools and the barriers that have made it more difficult to serve their kids. They described classrooms that are stifling hot without air conditioning, important books that are unavailable and supplies as basic as toilet paper that are sometimes in short supply.
As the strike entered its second week, Emanuel turned to the courts to try to force teachers back to the classroom by filing a lawsuit that described the walkout as an unlawful danger to the public.
The complaint sought a court order to end the strike, saying it was illegal because it endangered the health and safety of students and concerned issues - evaluations, layoffs and recall rights - that state law says cannot be grounds for a work stoppage.