he election of a Republican president opposed to the expansion of slavery into the western territories led seven states in the lower South to secede from the Union beginning in December 1860 and to establish the Confederate States of America the following February. After Lincoln notified South Carolina's governor that he intended to resupply Fort Sumter in Charleston harbor, the Confederacy fired on the installation. This led Lincoln to declare that an insurrection existed in the South. Within weeks, Virginia, North Carolina, Tennessee, and Arkansas joined the Confederacy.

2.1 million men served in the Union army and 900,000 Confederates in the Confederate. The Civil War was the first war to involve trench warfare; observation balloons; iron-clad ships; and the use of repeating and breech-loading rifles, mines, and hand grenades.

Early in the war, the Union succeeded in blockading Confederate harbors, and by mid-July 1862 it had divided the Confederacy in two by wresting control of Kentucky, Missouri, and much of Tennessee, as well as Mississippi River.

In the Eastern Theater in 1861 and 1862, the Confederacy stopped Union attempts to capture its capital in Richmond, Virginia. In September 1862 (at Antietam in Maryland) and July 1863 (at Gettysburg in Pennsylvania), Lee tried and failed to provoke European powers intervention in the war by winning a victory on Northern soil.

After futile pleas to the border states to free slaves voluntarily, Lincoln in the summer of 1862 decided that emancipation was a military and political necessity. The Emancipation Proclamation transformed the war from a conflict to save the Union to a war to abolish slavery. It authorized the enlistment of African Americans; 220,000 served during the war, helping to ensure the destruction of slavery.

Consequences

1. During the war Congress adopted policies that altered American society. The Homestead Act offered free public land to western settlers. Huge land grants supported construction of a transcontinental railroad. The government raised the tariff, imposed new taxes, enacted the first income tax, and established a system of federally-chartered banks.

2. The Union lost about 360,000 troops during the Civil War and the Confederacy about 260,000. This is almost as many soldiers as have died in all other American wars combined.

3. The 13th Amendment, ratified in December 1865, ended slavery in the United States.

Background

Between the Napoleonic Wars of the late eighteenth and early nineteenth centuries and World War I, the American Civil War was the greatest military conflict in the western world. It cost 600,000 American lives, more than in World War I and World War II combined. Its social consequences were especially far-reaching. The war resulted in the emancipation of four million enslaved African Americans. It also brought vast changes to the nation's financial system, fundamentally altered the relationship between the states and the federal government, and became modern history's first total war. It is truly the central event in American history.