The main outcome of the American Civil War was the preservation of the Union and the abolition of slavery. The conflict, fought between 1861 and 1865, was primarily rooted in disagreements over states' rights and the institution of slavery. The victory of the Union forces ensured that the United States remained intact, preventing the secession of Southern states. Additionally, the war led to the Emancipation Proclamation, which declared freedom for enslaved individuals in rebel states, culminating in the passage of the 13th Amendment, which abolished slavery throughout the nation and reshaped American society.