Charles Dickens is an objective third party viewer who hated slavery and was a staunch abolitionist. Have you ever heard of this legal concept called "statement against interest"? They are generally regarded as true, because people usually won't make statements against their interests unless they feel compelled to be truthful.
The Confederate politicians would lie about their true motivation in the same manner modern politicians lie about theirs.
The unassailable fact was that the Southern states would have reaped a huge cash windfall from leaving, and the Northern states would face a serious financial crises as a consequences.
You tell me it's about some moral issue, but when people who have a lot of money at stake tell me that the thing which will make them the most money is a major moral issue, I think their motivation is money, not morality.
Especially after they passed the Corwin Amendment. You simply cannot jive that vote with any moral stance for attacking the Confederates. The Northern states were all so willing to keep slavery indefinitely so long as they could keep their thumb on the Southern state's economic production.
Money. It's always money.
No, he was not. He looked way down his nose at Americans, thought they were crude, money hungry, and violent. He was pissed because international copyright didn't exist and American publishers were selling his work without royalties. He hardly even traveled in the South and the quotes attributed to him may not have even been his.