There are historians (and I know some personally) who will argue that the “cause” of the U.S. Civil War was not slavery: It was economics.
“Oh, yes, there were some abolitionists who sincerely were opposed to slavery,” the line goes. “But they were the tools of the industrial North, which wanted to destroy cheap labor in the South.” The proof? After the war, the Northern carpetbaggers came and forever changed the face of the nation, especially in the South.
Some others will argue it wasn’t about slavery or economics — it was about states’ rights.
Let’s concede for a moment that true abolitionists were a small minority and were manipulated by Northern robber-barons for their own purposes. Even so, you know who the Civil War remained “about slavery” to? The slaves. Economy, states’ rights… Pfftt! Fact is, when the war ended, the Constitution was amended to give an entire class of Americans rights guaranteed to them that they had never been given, despite being human beings. Before the Civil War, one man could own another in this country; after, they could not. That’s a big deal.