The Civil War

The American Civil War (1861–1865) was a civil war that took place in United States of America. In response to the election of Abraham Lincoln as President of the United States, eleven southern slave states declared their secession from the United States and formed the Confederate States of America ("the Confederacy"); the other twenty-five states supported the federal government ("the Union"). After four years of warfare, mostly within the Southern states, the Confederacy surrendered and slavery was outlawed everywhere in the nation. Issues that led to war were partially resolved in the Reconstruction Era that followed, though others remained unresolved.

In the presidential election of 1860, the Republican Party, led by Abraham Lincoln, had campaigned against the expansion of slavery beyond the states in which it already existed. The Republicans were strong advocates of nationalism and in their 1860 platform explicitly 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 together 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 country in the world recognized the Confederacy.

Hostilities began on April 12, 1861, when Confederate forces attacked a U.S. military installation at Fort Sumter in South Carolina. Lincoln responded by calling for a volunteer army from each state to recapture federal property, which led to declarations of secession by four more slave states. Both sides raised armies as the Union seized control of the border states early in the war and established a naval blockade. Land warfare in the East was inconclusive in 1861–62, as the Confederacy beat back Union efforts to capture...