The result of the 1861–1870 war in the United States, known as the American Civil War, was the preservation of the Union and the abolition of slavery. Following years of conflict between the North and South, culminating in the surrender of the Confederacy in 1865, the war resulted in the passage of the 13th Amendment, which formally abolished slavery. The war's outcome fundamentally transformed American society, paving the way for subsequent civil rights movements and struggles for equality.