The American Civil War was fought between 1861 to 1865 between the Northern and Southern states over the issues of slavery and states' rights. The central cause of the war was the dispute over whether slavery would be allowed to expand into the western territories. Some of the key events leading up to the war included economic and social differences between the North and South, the fight between slave and non-slave state proponents, and the election of Abraham Lincoln, who opposed the expansion of slavery. The majority of battles during the war took place in the states of Virginia and Tennessee.