The Common Core State Standards (CCSS) were developed in 2010 to provide a set of consistent targets across the United States for English [Page 330]language arts (ELA) and mathematics learning for public school students in Grades K–12. Described as college- and career-ready standards, they represented a shift from previous individual state-defined content standards that were often deemed to be low-level standards that did not meet the needs of students in a global economy. This entry provides an overview of the development of the CCSS and then describes the ELA and the mathematics standards. It details the history of adoption and rejection of the standards by states. In addition, the assessments developed to measure achievement of the CCSS are described.