Within days of the fall of Fort Sumter, four more states joined the Confederacy: Virginia, North Carolina, Tennessee, and Arkansas. The battle lines were now drawn.
On paper, the Union outweighed the Confederacy in almost every way. Nearly 21 million people lived in 23 Northern states. The South claimed just 9 million people — including 3.5 million slaves — in Confederate states. Despite the North's greater population, however, the South had an army almost equal in size during the first year of the war.
The North had an enormous industrial advantage as well. At the beginning of the war, the Confederacy had only one-ninth the industrial capacity of the Union. But that statistic was misleading. In 1860, the North manufactured 97 percent of the country's firearms, 96 percent of its railroad locomotives, 94 percent of its cloth, 93 percent of its pig iron, and over 90 percent of its boots and shoes. The North had twice the density of railroads per square mile. There was not even one rifleworks in the entire South.
All of the principal ingredients of gunpowder were imported. Since the North controlled the navy, the seas were in the hands of the Union.

License information: CC BY 4.0
MPAA: G
Go to source: https://www.commonlit.org/texts/a-nation-divided-north-vs-south