The American Civil War (1861–1865) was a bitter sectional conflict between the United States (the "Union") led by President Abraham Lincoln and politically dominated by his Republican Party; and the Confederate States of America, led by President Jefferson Davis, which moved to secede from the Union after Abraham Lincoln's 1860 election as President. Fighting commenced on April 12, 1861, when Confederate forces attacked a United States (federal) military installation at Fort Sumter in South Carolina and ended with the Confederate Army's April 9, 1865 surrender at Appomattox. After four brutal years of war and more than 970,000 casualties, including approximately 560,000 deaths, the controversies affected by the war's unresolved social, political, economic and racial tensions continu...more >>e to shape contemporary American thought. The causes of the war, the reasons for the outcome, and even the name of the war itself, are subjects of much controversy, even today.