heres ya a few more
Charles Dickens views on the subject:
Union means so many millions a year lost to the South; secession means the loss of the same millions to the North. The love of money is the root of this, as of many other evils. The quarrel between the North and South is, as it stands, solely a fiscal quarrel.
Karl Marx seconded this view:
The war between the North and the South is a tariff war. The war is further, not for any principle, does not touch the question of slavery, and in fact turns on the Northern lust for sovereignty
Clearly both Marx and Dickens were completely relevant key players in the Civil War with vast amounts of inside information on its causes.