In high school American history classrooms all over the country, the Civil War is a staple in the curriculum. Of course, that is to be expected given the pivotal place that the Civil War occupies in the nation's history. Indeed, it is not unusual for high school teachers to devote weeks of instruction to exploring the causes leading up to the war, the objectives and strategy of the Union and the Confederacy, the major turning points in the conflict, and the sweeping reforms initiated during Reconstruction. Nevertheless, there is evidence that, in spite of the efforts of their teachers, students may not engage in meaningful ways with the content of history classes and do not perform as well as might be expected on standardized history assessments. For example, a majority of high school students perform at the basic and below basic levels on the National Assessment of Educational Progress (2011). The project discussed in this article is an example of using a novel approach to engage students at Scottsbluff High School in western Nebraska in working with sources in order to build richer understandings of the content and promote critical thinking around major themes in American history. The project was designed to actively engage students in working with primary source material and statistical data in such a way as to equip students with more sophisticated understandings of sectional differences in the late antebellum period. Students located several categories of census data and manipulated that statistical information to create thematic maps that graphically captured the significant regional differences between North and South prior to the outbreak of the Civil War. The student-created cartograms visually illustrated the profound economic and demographic disparities between the northern and southern states, and provided context for analyzing the relative advantages and disadvantages of each section at the start of the war. Moreover, the cartograms were useful tools for exploring how those advantages and disadvantages influenced strategic decision making and the prosecution of the war by the Union and Confederacy. The activity required students to interact with the material in an innovative way in order to effectively manipulate and represent the data, and challenged students to engage in meaningful analysis and creative problem solving in producing and interpreting the cartograms. It was planned to ensure that students would acquire richer understandings of sectional differences and firmer ideas regarding how the North and South had developed along divergent paths during the antebellum period.