IntroductionA primary role of the Council of the Great City Schools is to support member districts in raising the achievement levels of all students. The Common Core State Standards (CCSS) have established rigorous expectations for student work at every grade level K-12. Our work is designed to support school districts in successfully implementing these standards to improve the achievement levels of all students. We focus on the development of effective tools, resources, and professional development to enable educators to raise the level of student performance. We collaborate with the writers of the Common Core and across organizations and districts to build a shared understanding of the instructional shifts and implications for curriculum and assessment. This collaboration will support teaching and learning in the nation's largest urban districts so that our children are college and career ready when they graduate from high school.