Causes of the Civil War have been argued for years. Some say State's Rights, some say Slavery.
Lincoln was an anti-slavery advocate, but at his inauguration he said he would not attempt to change states that had slavery in place. The Emancipation Proclamation was not issued until 2 years into the war.
I believe the problem was the North did not like the South's self sufficiency.
Cotton and Tobacco were exchanged for what ever they couldn't provide for themselves, and they didn't really become involved in the usury system till the carpet baggers came along after the war.
Did they die in vain? Depends on your viewpoint. Popular history does not tell the whole story.
HM