The United States and the Confederate States fought in the Civil War. Many Southern states left the Union in 1860-1861 and formed their own country to protect slavery. The United States thought that the Southern States were wrong to leave the Union, so they started a war that stretched across the country for several years. In 1865, the United States fought the Confederate States and won. This put an end to slavery in the whole entire nation.The North and South fought in the Civil War to end sectionalism.
Sectionalism was a big lead to the Civil War in the United States. It occurred because of