African American

From the infamous cornerstone speech...

...its foundations are laid, its cornerstone 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. This, our new government, is the first, in the history of the world, based upon this great physical, philosophical, and moral truth.

In 1865, trying to downplay the slavery bit, he stepped in it even deeper.....

Slavery was without doubt the occasion of secession; out of it rose the breach of compact, for instance, on the part of several Northern States in refusing to comply with Constitutional obligations as to rendition of fugitives from service, a course betraying total disregard for all constitutional barriers and guarantees.

OH! So it was a Constitutional question at the heart of the matter. A Constitutional question with roots in slavery. Epic fail, Alex. The forerunner of even greater epic fails at downplaying the obvious.....slavery was the reason for their treason, no matter how you define it, couch it or just plain lie about it.