As one observer characterized the alleged movement of slaves into the territories, the conflict was about an “imaginary negro in an impossible place”.
Another author wrote: “Though many of them doubted whether slavery would ever take permanent root in Kansas, they feared to yield a legal precedent which could later be used against them. And so they demanded a right which they could not actively use - the legal right to carry slaves where few would or could be taken.”
“The one side fought rancorously for what it was bound to get without fighting; the other, with equal rancor, contended for what in the nature of things it could never use.”
http://dzanime.tripod.com/apush/apush/ramsdell-jaffa.htm
One could make the point that Lincoln and the Republicans started a war over a ficticious issue....a Gulf of Tonkin kind of thing.