In this study, we explore rhetorical moves used by students in argumentative, analytical writing in a college-level world history course. Drawing on the system of Engagement within the Appraisal framework from Systemic Functional Linguistics, we investigate differences between higher-graded and lower-graded essays in the combinations and patterns of resources used to expand and contract dialogic space while building an argument. The results show that while both higher-graded and lower-graded essays made use of some of the same moves, the higher-graded essays did so in a way that consistently furthered an argument. In addition, the higher-graded essays showed a recurring pattern of Engagement resources used for including and interpreting source texts. These findings illustrate that beyond simply including Engagement resources, students need to learn how to use these resources in purposeful and strategic ways.