Historically, textbooks have taught that incompatibility between northern and southern economies caused the Civil War. The industrial revolution in the North, during the first few decades of the 19th century, brought about a machine age economy that relied on wage laborers, not slaves.
At the same time, the warmer Southern states continued to rely on slaves for their farming economy and cotton production. Southerners made huge profits from cotton and slaves and fought a war to maintain them. Northerners did not need slaves for their economy and fought a war to free them. Everything else, many textbooks claim, was tied to that economic difference and was anchored by cotton.
The agricultural economy was certainly one cause of the Civil War, but not the only one. Wars are never simple and neither are their causes. Many other factors that helped bring about the war are central to understanding America's past.
So what did start the Civil War—a war that divided the nation, destroyed crops, cities, and railroad lines, and claimed 630,000 lives? Many factors plunged the nation into chaos in 1861. Key political causes include the slow collapse of the Whig Party, the founding of the Republican Party, and, most important, the 1860 election of Abraham Lincoln as president.