Thread: Why did the North fight the Civil War?

With the 150th anniversary of the War Between the States coming up, it occurs to me that I am somewhat ignorant as to the exact causes. The common supposition is that the Civil War was "fought over slavery". That is, that the South wanted slaves and the North wanted to abolish it. The South seceeded, and the North fought to "preserve the Union" and out of pure compassion for the enslaved.

There are problems with this, of course. For one thing, there are quotes like this one, from Abraham Lincoln:

"I will say then that I am not, nor ever have been in favor of bringing about in anyway the social and political equality of the white and black races - that I am not nor ever have been in favor of making voters or jurors of negroes, nor of qualifying them to hold office, nor to intermarry with white people; and I will say in addition to this that there is a physical difference between the white and black races which I believe will forever forbid the two races living together on terms of social and political equality. And inasmuch as they cannot so live, while they do remain together there must be the position of superior and inferior, and I as much as any other man am in favor of having the superior position assigned to the white race."

Then there is the fact that the Emancipation Proclamation was not issued until three years into the war. Even then, it did not free the slaves living in the Northern states of Missouri, Kentucky, Maryland, the counties that later became West Virginia, or Delaware. Worse, it did not free the slaves living parts of Texas, Louisiana, or any of Tennesse, because by the time it was enacted those places had fallen into the hands of the Union! This proclamation, once studied, can only be seen as a war strategy, intended to attract the support of slaves who didn't realize the limitations. Also, it appears that the North saw the abolition of slavery as a means of disrupting the Southern economy.

The Confederate State of America seems to have many reasons for leaving the Union, including the size and intrusion of the central Federal government into the lives of the people. Also was the issue of State's Rights, putting a more local government above rather than below a more distant government of Washington beurocrats. Of course, the issue of slavery cannot be entirely ignored, as it was a large factor in many Southerners for wanting to leave the Union.

I can see why the Confederates fought agains the invasion of the Union army. They likely saw the war as a protection of their homeland. But why did the North fight? Based on my research, slavery could not have been the reason for the North to want to wage such a violent and bloody war. And could Lincoln have really wanted to kill so many Americans simply to preserve the Union, less than a century after the nations secession from England?