Abraham Lincoln's campaign against slavery was revealed in speeches he made between 1854 and his inauguration in 1861. During this time, he had retired from Congress to practice law, but was pulled back into politics by his opposition to Illinois Senator Stephen A. Douglas' drive to open up new territories as legal slave states. In those years, Lincoln developed possible plans for nationwide abolition.
Lincoln acknowledged how hard it would be to abolish slavery. “If all earthly power were given me,” he said, “I should not know what to do.” He imagined four possible scenarios, only the last of which he thought had any hope of success. “My first impulse would be to free all the slaves, and send them to Liberia.” He referred to the African nation as the “native land” of southern slaves, as if they were an alien presence in the United States despite having been here for generations. Yet however desirable colonization might be, Lincoln went on, “a moment’s reflection” revealed its impracticality. “If they were all landed there in a day, they would all perish in the next ten days; and there are not surplus shipping and surplus money enough in the world to carry them there in many times ten days.” So Lincoln’s first scenario—colonization to Liberia—was whisked aside as impractical. “What then?” he asked.
You can read of Lincoln's other three scenarios for abolishing slavery, none of which involved a bloody war between the states, at LitHub. -via Damn Interesting