A new report from the American Institutes for Research, co-authored by the Collaborative’s deputy director Joel Knudson, tells the story of how the CORE Districts came into existence and designed their early work together. The report documents the ways in which existing relationships and the political opportunity offered through California’s Race to the Top Round 2 application set the stage for a new 10-district partnership focused on Common Core implementation and teacher quality. It also describes the participant-identified outcomes from CORE’s early work and outlines considerations for other districts embracing models of cross-district collaboration. The full report and an accompanying brief with lessons for district leaders are both available on the AIR website.