The conflict fought between the North and South in the United States was the Civil War, which lasted from 1861 to 1865. Rooted in deep-seated issues like slavery, state rights, and economic differences, the war saw the Union (North) battle the Confederacy (South). Major battles included Gettysburg and Antietam, resulting in significant casualties on both sides. The war ultimately ended with the defeat of the Confederacy, leading to the preservation of the Union and the abolition of slavery through the 13th Amendment. This conflict profoundly altered the social, economic, and political landscape of the United States.