The Civil War was fought between 1861-1865 between the Union (Northern) states and the Confederate (Southern) states over the issues of states' rights and slavery. Over 620,000 soldiers died making it the bloodiest war in American history. Key battles included Fort Sumter, Antietam, Gettysburg, and Appomattox Court House where the South surrendered, ending the war. Reconstruction efforts after the war attempted to reunite the country and define citizenship and rights for freed slaves.