Sharkey told the crowd the union’s demands are “about way more than just pay. It is about dignity, about the fact that our schools suffer from critical staffing shortages,” he said, arguing “the funding is there” to hire the thousands of new employees the union seeks.

A coordinated strike with allied members of SEIU Local 73 is in the works. Members in purple shirts were also on hand Tuesday. SEIU’s more than 7,000 members in Chicago public schools, representing non-teacher staff like custodians, bus drivers, and special-education aides, have already authorized a strike. Local 73 also announced Tuesday that its roughly 2,500 members that worked for the Chicago Park District had also authorized a strike. They are required to provide five days' notice before walking out.

Local 73 Executive Vice President Jeffrey Howard said he that hoped together, the unions bring the city as close to a general strike as possible. During the 2012 walkout, CPS kept schools open in the morning, and the city worked closely with local parks and libraries to provide programming for children. Having parks and other CPS staff out picketing could complicate the city’s efforts to reduce the strike’s impact on parents.

“The Chicago Park District values the contributions made by the 2,400 SEIU members serving our parks. Over the past several months, we have negotiated in good faith with SEIU Local 73, making significant progress to improve working conditions at the bargaining table and to extend a significant wage increase for our lowest-paid workers over the next five years," district spokesperson Michele Lemons said in an email. The district says their proposal includes big increases for hourly attendants, instructors and recreation leaders. "As we move forward, we will continue to work toward an agreement that is mutually favorable for the Chicago Park District, its valued employees and city taxpayers.”

The night also featured speeches from actor John Cusack, Chicago Federation of Labor President Bob Reiter, Illinois Federation of Teachers President Dan Montgomery and several of the City Council’s most progressive members, including Alds. Susan Sadlowski Garza, 10th, Jeanette Taylor, 20th, Byron Sigcho Lopez, 25th, Rossana Rodriguez Sanchez, 33rd, and Carlos Ramirez Rosa, 35th, who served as emcee.

"You're not just going on strike for yourselves, you're going on strike for your children," said Reiter, wearing a red White Sox hat. "If it's time to strike, then fucking strike."