In Chicago, teachers at 15 Acero charter schools have walked off their jobs. It's the first ever charter school strike in the country.
Teachers say they work a longer school year, for less pay when compared to Chicago Public School teachers.
Teachers are also on strike in west suburban Geneva, impacting students at ten schools. There are no classes or activities for students Wednesday.
The school board says it is working to set up its next negotiation session and waiting for a response from the union.