Abraham Lincoln very much wanted to end slavery in the United State of America but he was rational enough to assume that doing so would require more than simply becoming president and signing its abolishment into law. The American Civil War was not fought to end slavery. It was fought to stop the rebellion and secession of slave states from the United States of America. The Southern states wanted to secede from the Northern states because they understood that Lincoln was going to work to end slavery with or without their support, during his presidency. However, even after ending the long and arduous American Civil War, slavery still thrived in the Southern states. The 13th Amendment to the US Constitution, ultimately ended the practice of slavery and slave trading. As the American Civil War was waning and it became apparent that the Confederacy would indefinitely lose to the Northern states, Lincoln fought hard to have Congress pass the 13th Amendment, so that it would be added to the United States of America Constitution. He signed it into law after the American Civil War ended, and doing so effectively ended slavery in the United States of America on December 6, 1865. Incidentally, the 13th Amendment passed the Senate on April 8, 1864 but was not signed into official law being that it is now part of the United States of America Constitution until 1865