What year did the effort to deploy the Common Core State Standards (CCSS) in the US begin?

The effort to deploy the Common Core State Standards (CCSS) in the United States began in 2009. In this year, a group of experts and educators from various states developed the CCSS in English Language Arts and Mathematics. The objective was to establish consistent learning goals for students across multiple states, ensuring they were prepared for college and career success. The standards aimed to provide clear expectations of what students should understand and be able to do at each grade level, promoting greater consistency and alignment in education systems nationwide. Thus, 2009 marks the beginning of the Common Core State Standards initiative in the United States.