The war between the North and South in the United States is known as the American Civil War. It lasted from 1861 to 1865 and primarily revolved around issues such as states' rights and slavery. The conflict began when several Southern states seceded from the Union, forming the Confederate States of America. Significant battles, including Gettysburg and Antietam, shaped the war's progress. The Civil War resulted in the preservation of the Union and led to the abolition of slavery, fundamentally transforming the social and political fabric of the United States.