Henry Darwin Rogers, General Map of the United States, Showing the Area and Extent of the Free & Slave-Holding States, and the Territories of the Union (1857)

Maps produced in the years leading up to the Civil War illustrated the political divisions that existed at the time and how sectionalism was becoming a national crisis that would ultimately erupt in conflict. This map, published by Henry Darwin Rogers in 1857, in the midst of Bleeding Kansas and around the same time as the Dred Scott decision, depicted free states and territories in green, and slave-holding states in red. The map illustrates the domestic slave trade that had allowed the expansion of slavery at the heart of sectional and political debates, showing "slave-importing" states in dark red and "slave-exporting" states in light red. Also labeled on the map is the Missouri Compromise Line, which the Kansas-Nebraska Act had essentially made null and void when it allowed Kansas citizens to vote on the legality of slavery in the state.