Humanities › History & Culture Major Battles of the Civil War Share Flipboard Email Print History & Culture Military History Civil War Battles & Wars Key Figures Arms & Weapons Naval Battles & Warships Aerial Battles & Aircraft French Revolution Vietnam War World War I World War II American History African American History African History Ancient History and Culture Asian History European History Genealogy Inventions Latin American History Medieval & Renaissance History The 20th Century Women's History View More By Robert McNamara History Expert Robert J. McNamara is a history expert and former magazine journalist. He was Amazon.com's first-ever history editor and has bylines in New York, the Chicago Tribune, and other national outlets. our editorial process Robert McNamara Updated July 24, 2019 The Civil War lasted for four violent years, and particular battles and campaigns stood out for having great influence on the eventual outcome. The Battle of Antietam Library of Congress The Battle of Antietam was fought on September 17, 1862, and became known as the bloodiest day in American history. The battle, fought in a valley in western Maryland, ended the first major Confederate invasion of northern territory. The heavy casualties on both sides shocked the nation, and remarkable photographs from the battlefield showed Americans in northern cities some of the horrors of the war. As the Union Army did not succeed in destroying the Confederate Army, the battle could have been viewed as a draw. But President Lincoln considered it enough of a victory to feel that it gave him political backing to issue the Emancipation Proclamation. Significance of the Battle of Gettysburg The Battle of Gettysburg, fought during the first three days of July 1863, proved to be the turning point of the Civil War. Robert E. Lee led an invasion of Pennsylvania which could have had disastrous consequences for the Union. Neither army planned to fight at the small crossroads town of Gettysburg, in southern Pennsylvania farm country. But once the armies happened to meet, a gigantic clash seemed inevitable. The defeat of Lee and his retreat into Virginia set the stage for the final bloody two years, and eventual outcome, of the war. The Attack on Fort Sumter Library of Congress After years of moving toward war, the outbreak of actual hostilities began when forces of the newly formed Confederate government shelled a United States military outpost in the harbor of Charleston, South Carolina. The attack on Fort Sumter did not matter much in a military sense, but it had profound consequences. Opinions had already been hardening during the secession crisis, but an actual attack on a government installation made it clear that the rebellion of the pro-slavery states would indeed lead to war. The Battle of Bull Run Liszt Collection/Heritage Images/Getty Images The Battle of Bull Run, on July 21, 1861, was the first major engagement of the Civil War. In the summer of 1861, Confederate troops were massing in Virginia, and Union troops marched southward to fight them. Many Americans, both in the North and in the South, believed that the conflict over secession might be settled with one decisive battle. And there were soldiers as well as spectators who wanted to see the war before it ended. When the two armies met near Manassas, Virginia on a Sunday afternoon both sides committed a number of errors. And in the end, the Confederates managed to rally and defeat the northerners. A chaotic retreat back toward Washington, D.C. was humiliating. After the Battle of Bull Run, people began to realize that the Civil War would probably not end soon and the fighting would not be easy. The Battle of Shiloh The Battle of Shiloh was fought in April 1862 and was the first enormous battle of the Civil War. During fighting spanning two days in a remote part of rural Tennessee, Union troops who had landed by steamboat slugged it out with Confederates who had marched to head off their invasion of the South. The Union troops were almost driven back to the river at the end of the first day, but on the following morning, a fierce counterattack drove the Confederates back. Shiloh was an early Union victory, and a Union commander, Ulysses S. Grant, gained considerable fame during the Shiloh campaign. The Battle of Ball's Bluff The Battle of Ball's Bluff was an early military blunder by Union forces early in the war. Northern troops who crossed the Potomac River and landed in Virginia were trapped and suffered heavy casualties. The disaster had serious consequences as an outrage on Capitol Hill led the U.S. Congress to form a committee to oversee the conduct of the war. The congressional committee would wield influence throughout the rest of the war, often vexing the Lincoln Administration. The Battle of Fredericksburg The Battle of Fredericksburg, fought in Virginia at the end of 1862, was a bitter contest that exposed serious weaknesses in the Union Army. Casualties in the Union ranks were heavy, especially in units that fought heroically, such as the legendary Irish Brigade. The second year of the war had begun with some optimism, but as 1862 ended, it was clear that the war would not end quickly. And it would continue to be very costly.