On November 6, 1860, in an election that brought the new Republican Party to national power, Abraham Lincoln was elected president by a strictly northern vote. At 4:30 a.m. on April 12, 1861, Confederate troops fired on Fort Sumter in South Carolina’s Charleston Harbor. Less than 34 hours later, Union forces surrendered. Traditionally, this event has been used to mark the beginning of the Civil War.

Source: United Stated Senate