There's no question that the Chicago Teachers Union has learned from the path set by similar groups in recent years. Per the Associated Press' Kathleen Foody and Don Babwin, the union wants the strike to be quick and efficient:

“We want this to be a short strike with an agreement that will benefit our schools and our teachers. We have a ways to go,” Chicago Teachers Union President Jesse Sharkey said during a union news conference. “We actually want to see improvement on all the issues we are talking about here.”

Chicago teachers are concerned about a number of issues including smaller class size, teacher pay, and contract length. But the union's most important focus is on providing affordable housing to the homeless student population in Chicago. Chicago public schools represent the third-largest school district in the nation, and according to the Chicago Tribune:

More than 16,450 Chicago Public Schools students didn’t have a permanent home during the 2018-19 school year, according to numbers released Thursday by the Chicago Coalition for the Homeless.

The Washington Post's Kim Bellware reports:

This contract negotiation marks the first time the union has expressly called on the city to address systemic housing equity (Illinois law restricts the set of issues over which teachers may legally strike). It’s part of a growing movement, spearheaded by teacher and other labor unions, focused more broadly on issues affecting their community for what’s often called “bargaining for the common good.”

The Chicago Teachers Union is taking a stand: no child should leave school unsure of where they will sleep. The group is demanding the city "commit to creating sustainable housing, housing subsidies for lower-paid school staffers such as aides, and a support system for homeless students." A large-scale strike is one of the few ways to force action in these areas.