The American Civil War officially began on April 12, 1861, when Confederate forces fired upon Fort Sumter in South Carolina. This conflict arose from growing tensions over slavery, states' rights, and economic differences between the Northern and Southern states. The attack on Fort Sumter was the first military engagement of a war that would last four years, leading to profound changes in the United States. The Civil War resulted in the preservation of the Union, the abolition of slavery, and significant political and social transformations. It remains a pivotal event in American history, shaping the nation’s principles and its ongoing struggles with race and equality.