The Civil War began Apr 12, 1861

150 years ago today, April 12, 1861 Confederate shore batteries under General P.G.T. Beauregard open fire on Union-held Fort Sumter in South Carolina's Charleston Bay. During the next 34 hours, 50 Confederate guns and mortars launched more than 4,000 rounds at the poorly supplied fort. On April 13, U.S. Major Robert Anderson surrendered the fort. Two days later, U.S. President Abraham Lincoln issued a proclamation calling for 75,000 volunteer soldiers to quell the Southern "insurrection."
As early as 1858, the ongoing conflict between North and South over the issue of slavery had led Southern leadership to discuss a unified separation from the United States. By 1860, the majority of the slave states were publicly threatening secession if the Republicans, the anti-slavery party, won the presidency. Following Republican Abraham Lincoln's victory over the divided Democratic Party in November 1860, South Carolina immediately initiated secession proceedings.
http://www.civilwar.org/150th-anniversary/