Hiya!

Slavery was, far and away, the dominant cause of the Civil War. There were, of course, other contributing factors, however. These included the states' rights (to own slaves), the economics of slavery and its centrality to the prosperity of white southern slave-owners, and the loss of southern dominance in federal affairs, caused by the growing strength and influence of non slave states.

/u/Georgy_K_Zhukov explains the dominant role of slavery in the Civil war in fascinating, exhaustive detail in this post. I'm confident it will answer your question in far more detail than I could ever hope to.

I hope this helps!

As a whole the issue was economics.

The South held strongly to their agricultural roots and were in control of one of the largest sectors of wealth in the country "King Cotton". This industry utilized a very large slave force and it would cause ruin to the Southern economy and it's political hold once abolition was put into effect.

This great wealth and the 3/5 rule left the South in control of much of the political sectors at the time. Also throw in the dissolution of the Union after Secession and the desire to keep the country united was one of the many factors that drove the Civil War.

"The Civil War And Reconstruction" by J. G. Randall and David Herbert Donald http://americanhistory.about.com/od/civilwarmenu/a/cause_civil_war.htm http://www.historynet.com/causes-of-the-civil-war http://www.pbs.org/opb/historydetectives/feature/causes-of-the-civil-war/