One of the reasons for the United States Civil War was the inability to adequately address the issue of slavery. Abolitionism was a growing , worldwide concern. The Dred Scott decision added to the growing anti-slavery sentiment. With westward expansion the Missouri Compromise failed to resovle slavery in those areas. The Civil War was an explosion of this and other issues that could not be solved legally or diplomatically. In 1865 the 13th amendment to the Constitution abolished slavery and the 14th amendment defined citizenship , guaranteed the rights of citizens and equal protection under the law. It prevents states from denying due process to its citizens. The addition and clarification of these are significant because they legally uphold the end of slavery and the rights of former slaves as citizens