Seventy 8th-grade students (including talented writers, those with average ability, and students in need of special education services) participated in an integrated social studies and language arts unit designed to promote historical understandings and argumentative writing skills. The historical reasoning instruction lasted 12 days, and the writing instruction lasted 10 days. Students applied historical inquiry strategies when reading documents related to westward expansion and learned to plan argumentative essays related to each historical event. Results indicate that in comparison to 62 students in a control group who did not receive either form of instruction, students who demonstrated mastery of the target strategies during instruction wrote historically more accurate and more persuasive essays regardless of their initial learning profile.