Composer is the first digital platform to offer a comprehensive collection of high quality content and resources for citizenship education. In 2019, Composer was founded as a collaborative partnership among five organizations with a shared commitment to preparing a new generation of engaged citizens: High Resolves, Facing History and Ourselves, iCivics, Generation Citizen, and Peace First. Composer’s ecosystem has grown to include dozens of the world’s leading curriculum providers in civics, social and emotional learning, social justice, and global competence. Composer has curated nearly 1,000 powerful learning experiences and built a design-interface grounded in learning science to support educators with curriculum planning. After a successful private beta of 455 users from 113 schools across the US, Australia, and Canada, Composer will be publicly available as a free tool for educators starting April 2020.