Perhaps the greatest challenge that can befall a nation is a conflict that results in a civil war. The United States, after barely being in existence as a constitutional government for only 72 years, experienced such an event in 1861. The reasons for the division between the North and the South centered on the slavery question and its economic effects, the tariffs-which mostly affected the South-and the unresolved issue of states' rights. The American Civil War remains as the most violent time in the history of the United States. More than 620,000 men lost their lives in the war. The war left a long-lasting resentment by the South against the North. The aftermath also created new problems, especially with regard to Reconstruction efforts.