Writing proficiency is important for academic and professional success, yet only one-third of US students write at proficient levels. While Self-Regulated Strategy Development (SRSD) has shown effectiveness across different populations, few studies have examined its application in elementary social studies contexts. This study investigated the implementation of STOP DARE+, an SRSD-based writing intervention incorporating reading from social studies source texts and perspective-taking, in a fourth-grade social studies classroom studying the Underground Railroad. The intervention was delivered across 11 sessions to 12 students with diverse learning needs. Writing quality was assessed using the newly developed Multidimensional Spectrum of Holistic Writing Quality scoring tool, alongside genre elements and text production measures. Social validity was evaluated through the Teacher-Informed Perspectives Snapshot (TIPS), a new repeated-measures tool, combined with interviews and student focus groups. Results showed significant improvements in all writing measures with large effect sizes. Students and teachers reported strong positive perceptions of the intervention’s effectiveness and meaningfulness, with students particularly emphasizing the importance of perspective-taking for both academic and social development. The findings suggest that integrating SRSD-based writing instruction with social studies content can enhance both writing skills and critical thinking while fostering deeper engagement with historical events and social justice themes.