Elementary pre- and in-service educators increasingly rely on online instructional resources to supplement their curriculum. As social studies instruction has received progressively less attention in elementary classrooms, prospective teachers have fewer opportunities to observe powerful and purposeful elementary social studies pedagogy. To develop critical analysis of instructional resources found on for-profit marketplaces like Pinterest and Teachers Pay Teachers, students in a Midwestern teacher preparation program completed an assignment that required them to analyze online resources with a critical media literacy tool. In this qualitative study the authors conducted a content analysis of 10 of these assignments, all related to Martin Luther King, Jr., Black History Month, and the Civil Rights Movement. Through cycles of coding, the authors identified resources with problematic historical narratives, student assumptions about creator expertise and resource credibility, and the challenges of relying on a checklist for critical analysis. While the critical media literacy tool was helpful in directing preservice teachers' attention toward meaningful social studies content, it was insufficient as assigned. The authors found that the tool failed to deeply contextualize racial platform capitalism and the need for critical race media literacy in assessing lessons about Black history.