The Fourteenth Amendment was passed in 1868, at the conclusion of the Civil War, and its ratification was a condition of the southern states regaining representation in Congress.
The Confederacy was founded on the notion of white supremacy. You should refer to the founding documents - the declaration of causes of the various southern states, the statements of the leaders of the Confederate movement - they explicitly stated that the defining difference between the Southern and Northern states was the issue of race, and what rights should be accorded to people of African descent.
A particularly famous speech is the "Cornerstone speech" of Alexander Stephens, the vice-president of the Confederacy:
Our new government is founded upon exactly the opposite idea; its foundations are laid, its corner- stone rests upon the great truth, that the negro is not equal to the white man; that slavery -- subordination to the superior race -- is his natural and normal condition. [Applause.] This, our new government, is the first, in the history of the world, based upon this great physical, philosophical, and moral truth. This truth has been slow in the process of its development, like all other truths in the various departments of science. It has been so even amongst us. Many who hear me, perhaps, can recollect well, that this truth was not generally admitted, even within their day. The errors of the past generation still clung to many as late as twenty years ago. Those at the North, who still cling to these errors, with a zeal above knowledge, we justly denominate fanatics. All fanaticism springs from an aberration of the mind -- from a defect in reasoning. It is a species of insanity. One of the most striking characteristics of insanity, in many instances, is forming correct conclusions from fancied or erroneous premises; so with the anti-slavery fanatics; their conclusions are right if their premises were. They assume that the negro is equal, and hence conclude that he is entitled to equal privileges and rights with the white man.
Edit: let me break out that last sentence for you, in case you didn't read all the way through: "They assume that the negro is equal, and hence conclude that he is entitled to equal privileges and rights with the white man."
Edited 11/29/2015 00:10:07