American Civil War (1861–1865) occurred after eleven Southern slave states declared their secession from the United
States and formed the Confederate States of America. Led by Jefferson Davis, the Confederacy fought against the
United States (the Union), which was supported by all the free states
(where slavery had been abolished) and by five slave states that became
known as the border states.
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
Both sides raised armies as the Union assumed control of the border
states early in the war and established a naval blockade. In September
1862, Lincoln's Emancipation Proclamation made ending slavery in the
South a war goal, and dissuaded the British from intervening.
Confederate commander Robert E. Lee won battles in the east, but in
1863 his northward advance was turned back with heavy casualties after
the Battle of Gettysburg.
In the west, the Union gained control of the
Mississippi River after their capture of Vicksburg, Mississippi,
thereby splitting the Confederacy in two.
The Union capitalized on its long-term advantages
in men and material and by 1864 Ulysses S. Grant fought battles
of attrition against Lee, while Union general William Tecumseh Sherman
captured Atlanta and marched to the sea. Confederate resistance ended
after Lee surrendered to Grant at Appomattox Court House on April 9,
The American Civil War
is the deadliest war in American history, resulting in the deaths of
620,000 soldiers and an undetermined number of civilian casualties.
Ten percent of all Northern males 20–45 years of age died, as did 30
percent of all Southern white males aged 18–40.
Victory for the North meant the end of the Confederacy and of slavery
in the United States, and strengthened the role of the federal
government. The social, political, economic and racial issues of the
war decisively shaped the reconstruction era that lasted to 1877.