The Union line was laid out in a defensive formation resembling a fishhook. On the second day of battle, most of both armies had assembled. However, two large Confederate corps assaulted them from the northwest and north, collapsing the hastily developed Union lines, sending the defenders retreating through the streets of the town to the hills just to the south. Low ridges to the northwest of town were defended initially by a Union cavalry division under Brigadier General John Buford, and soon reinforced with two corps of Union infantry. Prodded by President Abraham Lincoln, Major General Joseph Hooker moved his army in pursuit, but was relieved of command just three days before the battle and replaced by Meade.Įlements of the two armies initially collided at Gettysburg on July 1, 1863, as Lee urgently concentrated his forces there, his objective being to engage the Union army and destroy it. With his army in high spirits, Lee intended to shift the focus of the summer campaign from war-ravaged northern Virginia and hoped to influence Northern politicians to give up their prosecution of the war by penetrating as far as Harrisburg, Pennsylvania, or even Philadelphia. Īfter his success at Chancellorsville in Virginia in May 1863, Lee led his army through the Shenandoah Valley to begin his second invasion of the North-the Gettysburg Campaign. The battle involved the largest number of casualties of the entire war and is often described as the war's turning point due to the Union's decisive victory and concurrence with the Siege of Vicksburg. Lee's Army of Northern Virginia, halting Lee's invasion of the North. In the battle, Union Major General George Meade's Army of the Potomac defeated attacks by Confederate General Robert E. The Battle of Gettysburg ( locally / ˈ ɡ ɛ t ɪ s b ɜːr ɡ/ ( listen)) was fought July 1–3, 1863, in and around the town of Gettysburg, Pennsylvania, by Union and Confederate forces during the American Civil War.