I will neither conceal my gratification nor restrain the expression of my gratitude that the Union people, through their convention, in their continued effort to save and advance the nation, have deemed me not unworthy to remain in my present position. I know no reason to doubt that I shall accept the nomination tendered; and yet perhaps I should not declare definitely before reading and considering what is called the platform. I will say now, however, I approve the declaration in favor of so amending the Constitution as to prohibit slavery throughout the nation. When the people in revolt, with a hundred days of explicit notice that they could within those days resume their allegiance without the overthrow of their institution, and that they could not so resume it afterward, elected to stand out, such amendment of the Constitution as now proposed became a fitting and necessary conclusion to the final success of the Union cause. Such alone can meet and cover all cavils. Now the unconditional Union men, North and South, perceive its importance and embrace it. In the joint names of Liberty and Union, let us labor to give it legal form and practical effect.
Abraham Lincoln, Reply to the Committee Recommending Nomination Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/289355