We are creating an intervention consisting of professional development and various teacher- and student-facing tools to support argumentative writing in secondary school history classes. UCLAIMS is being developed from the research-based Pathway, C3WP, and SRSD interventions and our own exploratory work in secondary school history classes. We expect to test it in a randomized controlled trial during the 2022-23 school year. The UCLAIMS web page will highlight our exploratory work, some of our research measures, and, after the completion of the RCT, our intervention materials.