Who was the leading official of the Confederate States of America that gave the "Cornerstone" speech?

Alexander Stephens was vice president of the Confederacy. He is remembered for giving his "cornerstone" speech on March 21,1861. This speech was given as a full, unguarded public exposition for the reasons for Southern Independence as slavery.

To quote, "Our new government is founded upon exactly the opposite of (Jefferson's) ideas: its foundations are laid, it's 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 moral condition." No mention of states rights was ever mentioned.