After Abraham Lincoln was elected president in 1860, the southern states started to secede from the Union. The first state to secede (aka leave) the Union was South Carolina, which left roughly one month after Lincoln was elected. After South Carolina left, 6 other states would secede within the next three months. These states developed their own nation known as the Confederate States of America. This secession would spark conflict between the North and South, resulting in the American Civil War.