"Map of the United States, showing by colors, the Area of Freedom and Slavery, and the Territories whose destiny is yet to be decided, exhibiting also the Missouri Compromise Line and the routes of Colonel Fremont in his Famous Explorations with important statistics of the Free and Slave States," 1865. Courtesy of the Norman B. Leventhal Map Center at the Boston Public Library via Digital Commonwealth. More info
Most Civil War timelines begin in April 1861 with the Confederate firing on Fort Sumter, a federal facility in South Carolina which had seceded five months earlier. Those shots were the technical start of the war but the underlying causes had been present for decades. Diversity had been the hallmark of the individual thirteen colonies, but becoming a nation took more than merely declaring independence.
These fledglings shared a common purpose. Hard work would result in the virtue and dignity necessary to participate in a republic. Yet tensions did not ebb as the founders had hoped, nor could compromise and political balance serve as a safeguard against increasing differences of economics, politics and moral sensibilities as the nation expanded physically and demographically.
Each side, South and North, slave and free, believed that it was the legitimate heir to fulfill the nation's destiny but they became so incompatible that the differences threatened to truly "tear the nation in two."