The American Civil War in 11 Pictures - 3/11
South Carolina was the first state to secede in December 1860. Six more states (dark red) seceded in January/February 1861. Four more states left the Union a few months later (light red) and called themselves the Confederate States of America. To their opinion, they were sovereign states within the Union and thus had the right to leave whenever they liked, whereas the Northern states found the Union was only possible if all member states were and stayed united. The North therefore didn't recognize the secession as legal.