The Chicago Teachers Union's "Day of Action" sought to highlight stalled contract negotiations with Mayor Rahm Emanuel
's school board and to criticize Republican Gov. Bruce Rauner over a state budget stalemate that jeopardizes classroom funding.
Protesters temporarily blocked traffic on Lake Shore Drive, causing significant traffic snarls during Chicago's busy Friday evening commute. Three protesters were arrested, Chicago Police spokesman Kevin Quade told CNN, and charges are pending.
One person was also ticketed during the march. Police said they had no reports of injuries or property damage.
The strike was the latest setback for a city that has been reeling from record violence,
and Friday's 27,000-teacher walkout could presage a longer strike over a new contract. The last Chicago teachers strike was in 2012
and lasted more than a week until teachers and the mayor reached an agreement.
On Friday, teachers and students rallied outside Northeastern Illinois University and staged a theatrical "New Orleans-style jazz funeral" to describe Chicago schools' state of affairs.
Other striking teachers picketed in the Friday rain -- some with signs, some with umbrellas.
"We're fighting for not only our own contract but for better funding across the entire state. As you can see, there's tons of people out here from all walks of life," one striking teacher told CNN.
"We care about the students," the teacher added. "We want funding for our schools so our children can have supplies ... gym, art and P.E., just like the kids in the suburbs do."
Another striking teacher said, "It's showing solidarity. It's everybody standing together and saying we're not going to take this anymore."
The Chicago mayor visited one of 250 contingency centers that gave students a safe place to spend Friday.
The governor condemned
the job action.
"It's shameful that Chicago's children are the victims in this raw display of political power," Rauner said in a statement.
"Walking out on kids in the classroom, leaving parents in the lurch and thumbing their nose at taxpayers -- it's the height of arrogance from those we've entrusted with our children's futures," the governor added.
Rauner said he wants to pass a budget with the General Assembly that increases school funding but added he also seeks "much-needed reforms that put taxpayers back in control of their local governments and school districts."