Abraham Lincoln’s chief goal in the American Civil War was to preserve the Union. At the outset of the war, he would have done so at any cost, including by allowing slavery to continue. But abolishing slavery would become a nonnegotiable objective for him as the war progressed because of his own long-expressed abhorrence for the practice and because of the growing antislavery sentiment among his fellow Northerners. His intransigence on the subject scuttled possibilities of a peace conference between the Union and the Confederacy in 1864. By winning the war, he achieved both these objectives—reunion and abolition.