American Civil War

The American Civil War, in the United States often referred to as simply the Civil War and sometimes called the "War Between the States", was a civil war fought over the secession of the Confederate States. Eleven southern slave states declared their secession from the United States and formed the Confederate States of America; the other 25 states supported the federal government. After four years of warfare, mostly within the Southern states, the Confederacy surrendered and slavery was abolished everywhere in the nation. Issues that led to war were partially resolved in the Reconstruction Era that followed, though others remained unresolved.

History
In the presidential election of 1860, the Republican Party, led by Abraham Lincoln, had campaigned against expanding slavery beyond the states in which it already existed. The Republicans strongly advocated nationalism, and in their 1860 platform they denounced threats of disunion as avowals of treason. After a Republican victory, but before the new administration took office on March 4, 1861, seven cotton states declared their secession and joined to form the Confederate States of America. Both the outgoing administration of President James Buchanan and the incoming administration rejected the legality of secession, considering it rebellion. The other eight slave states rejected calls for secession at this point. No foreign governments recognized the Confederacy.