A tentative contract was reached between the Chicago Teachers Union and the Chicago Public Schools. But just in case things didn't work out, stacks of picket signs were ready for pick-up outside the union's strike headquarters on Monday. Charles Rex Arbogast/AP hide caption

toggle caption
Charles Rex Arbogast/AP

Striking Chicago public school teachers outside of George Westinghouse College Prep high school earlier today. Scott Olson/Getty Images hide caption

toggle caption
Scott Olson/Getty Images

A crowd of Chicago public school teachers marches past John Marshall Metropolitan High School on Wednesday, Sept. 12. Sitthixay Ditthavong/AP hide caption

toggle caption
Sitthixay Ditthavong/AP