The United States Census of 1860 was the eighth Census conducted in the United States starting June 1, 1860, and lasting five months. It determined the population of the United States to be 31,443,321, an increase of 35.4 percent over the 23,191,875 persons enumerated during the 1850 Census. The total population included 3,953,761 slaves, representing 12.6% of the total population.
By the time the 1860 census returns were ready for tabulation, the nation was sinking into the American Civil War. As a result, Census Superintendent Joseph C. G. Kennedy and his staff produced only an abbreviated set of public reports, without graphic or cartographic representations. The statistics did allow the Census staff to produce a cartographic display, including preparing maps of Southern states, for Union field commanders. These maps displayed militarily vital topics, including white population, slave population, predominant agricultural products (by county), and rail and post road transportation routes.