The major conflict fought between Northern and Southern states in the U.S. was the American Civil War, which lasted from 1861 to 1865. The war primarily centered around issues of slavery, states' rights, and economic differences. Southern states sought to preserve their agrarian economy and social order which relied heavily on enslaved labor, while Northern states, experiencing industrial growth, were increasingly against the expansion of slavery. The conflict led to significant loss of life and massive destruction, ultimately culminating in the defeat of the Confederacy. It also resulted in major changes within the United States, including the abolition of slavery and the Reconstruction Era efforts to integrate formerly enslaved individuals into society.