In the history of the United States of America, no other issue has been as contentious as the issue of slavery - which first dominated the social spectrum and then dominated the political spectrum of the country. Slavery existed in the United States as a legal institution for more than a century from 1619, when the first group of African slaves set foot in Virginia (the first English colony in North America,) to 1865, when it was abolished by an amendment to the U.S. Constitution. Which Amendment Ended Slavery in the United States? While the question can be answered in one line, it wouldn't do justice to the historic amendment of the U.S. Constitution which brought about a drastic change in the way Americans think today. In such circumstances, it would be better to go through a timeline which stresses on various events that formed the basis of this amendment. When we talk about the events which formed the basis of this historic amendment, the first thing to take into consideration is probably the American Civil War, which was triggered when the eleven Southern slave states decided to secede from the Union and formed the Confederate States of America. Even though there were various attempts to curb slavery previously, none was as concrete as the introduction of the Emancipation Proclamation in course of the Civil War. This executive order issued by the then President of the United States - Abraham Lincoln, gifted freedom to all slaves from the Confederate States which unsuccessfully tried to secede from the Union. Slavery was one of the main reasons for the outbreak of Civil War as it put the people from the industrialized Northern States and agrarian Southern States at loggerheads. The Southerners were in favor of slavery as it provided them with cheap labor to work at their plantations, and when they realized that the Northern States were lobbying for its abolishment they concluded that secession was the only way out. In the meanwhile, on 22nd September, 1862, President Abraham Lincoln, announced that he would issue a formal emancipation of all the slaves from the Confederate States if they did not return to the Union by 1st January, 1863. When none of the states returned by the given deadline, he issued the Emancipation Proclamation on 1st January, 1863. This step from the U.S. President meant freedom for more than 3 million slaves in the United States. This was the point when the emancipation of slaves became the focal point of American Civil War with some states lobbying for slavery, and others against it. While the introduction of Emancipation Proclamation brought to an end to the concept of slavery in the states which tried to secede from the Union, the same continued unabated in states like Missouri, Delaware and Kentucky, which didn't attempt to secede. It was believed that the war powers of the U.S. President were only restricted to regions which had attempted a rebellion. Taking that into consideration, the Congress of the United States began working on bringing about an end to slavery in the remaining parts of the United States of America and proposed the Thirteenth Amendment to the United States Constitution which eventually ended slavery in the country. 13th Amendment: End of Slavery It was the thirteenth amendment to the Constitution of the United States, which formally brought to an end to the century old institution of slavery in the country. It stated that concepts like slavery and involuntary servitude didn't have a place in the United States or any region under its jurisdiction, unless it was a part of the punishment process backed by proper conviction of the person in question. The 13th Amendment was approved by the U.S. Congress in January, 1965, and sent for ratification by states. Ratification of the amendment by three-fourth of the total states was mandatory for it to be added to the Constitution, and that was achieved on 18th December, 1865, when the Congress succeeded in getting it ratified from the required number of states. Whether the country would have been same without this amendment is a subject of debate; and that isn't quite surprising as most of the historical events, if not all, fall in the 'debatable' category at some or the other point of time.