How America Has Changed Since the First Census in 1790

1860: Census data used for Union Army maps

• U.S. resident population: 31,443,321
• Number of official states: 33
• Median age of population: 19.4
• Immigrants obtaining legal resident status: 153,640
• Biggest cities: New York, NY (Population: 813,669), Philadelphia, PA (565,529), Brooklyn, NY (266,661)

With the Civil War looming, cartographers used information from the 1860 census—such as slave populations rail routes, and agricultural products by county—to draw up maps for Union field commanders.

Casualties in the war (620,000) represent 2% of the entire population. With numbers adjusted for today’s population, that would be like losing 6.2 million people in a war.