The sectional crisis sparked tremendous creativity in mapmaking, as Northerners began to use maps to measure the extent of slavery. This includes the first statistical maps of population made in the United States, which even captured the attention of President Lincoln during the Civil War.
Anti-slavery activist John Jay used this map to alert northerners to the threat of slavery in the west, and to promote the cause of the newly-founded Republican Party in the 1856 presidential election.
In this iconic portrait, Carpenter carefully reproduced the Coast Survey’s map of slavery in the lower right corner after noticing Lincoln’s attention to it.
