The MCSS project, Extending the Reach of Primary Sources – English-Learner Collaborations, seeks to bring together teachers and also experts on English language development and History and Social Studies leaders. Using expert guidance, we are working with Massachusetts classroom teachers across grade levels to develop practical examples of classroom activities that strengthen language fluency and literacy for all learners, especially multilingual students using social studies primary sources. ¶ In the first year of the project we worked on language-aware primary source approaches for social studies classroom. In the second year, we developed examples of primary source lessons that can be used in stand-alone English Language Development classes in Massachusetts and in other states around the country. In the third year of the project, we are developing a teacher guide for scaffolding Document-Based Question materials and writing prompts for beginning and intermediate English learners. ¶ The grant funds stipends to teachers that participate in in pilot tests of new material, and to teachers who participate in Professional Learning Communities (PLCs) that pair English Language Development teachers with History and Social Studies teachers, in addition to materials development and the fostering of collaborative connections among organizations.