School board officials have repeatedly described the two sides as being close and suggested bargaining could be wrapped up quickly with agreements on the evaluations and a dispute about the recall of teachers who lose their jobs.
Earlier, Mayor Rahm Emanuel reiterated his belief that the strike could have been avoided altogether. At an appearance with principals and former principals, he addressed a sticking point over how teachers are hired, insisting that principals - not the city or the union - should have full control to pick their teams.
"I don't think downtown should be in the business of selecting teachers that the local school principal should select if you're going to hold them accountable," Emanuel said, as several hundred protesting teachers chanted and banged on drums.
Meanwhile, parents and caregivers were once again scrambling to figure out what to do with more than 350,000 idle children. On Monday, only about 18,000 students showed up at schools and other venues where authorities organized activities and provided meals for those in need. That means the vast majority of parents have to make alternative arrangements or leave their children unsupervised through the day.
The walkout - less than a week after most schools opened for fall - has created an unwelcome political distraction for Emanuel. In a year when labor unions have been losing ground nationwide, the implications were sure to extend far beyond Chicago, particularly for districts engaged in similar debates.
"This is a long-term battle that everyone's going to watch," said Eric Hanuskek, a senior fellow in education at the Hoover Institution of Stanford University. "Other teachers unions in the United States are wondering if they should follow suit."
The union had vowed to strike Monday if there was no agreement on a new contract, even though the district offered a 16 percent raise over four years and the two sides had essentially agreed on a longer school day. With an average annual salary of $76,000, Chicago teachers are among the highest-paid in the nation, according to the National Council on Teacher Quality. But some teachers said raises were less important to them than other issues.