[Rhetorically addressing southerners:] Your purpose, then, plainly stated, is that you will destroy the Government, unless you be allowed to construe and enforce the Constitution as you please, on all points in dispute between you and us. You will rule or ruin in all events.... The question recurs, what will satisfy them? Simply this: We must not only let them alone, but we must somehow, convince them that we do let them alone. This, we know by experience, is no easy task... [W]hat will convince them? This, and this only: cease to call slavery wrong, and join them in calling it right. And this must be done thoroughly - done in acts as well as in words. Silence will not be tolerated - we must place ourselves avowedly with them.Introduction to (and explanation of) this quote series can be found here. Read this tag to see all of them.
—Abraham Lincoln, "Cooper Union Speech", February, 1960