Was it about slavery? Yes and no. The other answerers were correct in stating that the Civil War was about States Rights, HOWEVER, it was indirectly about slavery too, as the overburdening question was, did states have the RIGHT to allow slavery or did the federal government have jurisdiction over what states could or could not do. All of my ancestors that were alive at that time fought for the Confederate State of Mississippi. The war basically demonstrated that the constitution was too weak, if states were able to leave the union at there will, it would very difficult to maintain the United States of America. Also in regards to Northern Manufacturing, people have apparently FORGOTTEN, that GREAT BRITAIN, was a major consumer of southern cotton, and even considered military intervention on the side of the south, so that they might receive more of that cotton. Also at that time, the French had moved large elements of the foreign legion into Mexico, and set up a government under an Austrian regent. Had the south "won" it would have left both the Union and Confederate states severely crippled, and, in the case of the south, open to invasion from French forces in Mexico. My great uncle flew the confederate flag above the American flag until his death. Flying that flag is more about showing Southern Pride. Some groups take that to mean being proud of being southern, others mean it to be tough, and still others use it as racist. Edit: The reason the Emancipation Proclamation freed slaves only in southern states, was because there were very few slaves in the North, and it was a display of the federal governments power.