The war fought between 1861 and 1865 in the United States is the American Civil War. This pivotal conflict emerged primarily over issues such as slavery, states' rights, and economic disputes between the agrarian South and the industrial North. The war resulted in significant societal, political, and economic changes, ultimately leading to the abolition of slavery with the 13th Amendment. Key battles included Gettysburg, Antietam, and Fort Sumter. The conflict led to profound consequences, including Reconstruction, the expansion of federal power, and enduring divisions in American society. Its legacy continues to influence discussions on race, equality, and state versus federal authority.