In this study, the effects of a disciplinary reading and writing curriculum intervention with professional development are shared. We share our instructional approach and provide writing outcomes for struggling adolescent readers who read at or below basic proficiency levels, as well as writing outcomes for proficient and advanced readers. Findings indicate significant and meaningful growth of about 0.5 of 1 standard deviation in students' abilities to write historical arguments and in the length of their essays for all participants, including struggling readers. Our study also considers teacher implementation of the curriculum intervention. We found that teachers who were most faithful to the underlying constructs of our curriculum intervention also made successful adaptations of the lesson materials.