In his Inaugural Address in March, Lincoln did not object to the proposed Thirteenth Amendment, which would make slavery untouchable and potentially reunite the union. But Lincoln did swear that he would never allow the extension of slavery. On March 21, the Confederacy’s vice president, Alexander Stephens, responded to Lincoln’s pledge in an extemporaneous speech. The Confederate government, he declared, rested “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.” This “great… truth,” Stephens said, was the “corner-stone” of the Confederacy. The speech became known as his “Cornerstone Speech.”
Ibram X. Kendi in Stamped From the Beginning