What was the conclusion of the Battle of Gettysburg?

Union and Confederate forces battled for the town of Gettysburg, Pennsylvania from July 1-3, 1863. After two days of bloody combat, the battle was in a stalemate by July 3rd. For the Union, this constituted a success, as their major aim of the battle was to halt Confederate General Robert E Lee's advance through Federal territory. However, for the Confederacy, this quagmire was a drain on resources and they needed to finish the battle swiftly, else face food, water and ammunition shortages.
So, Lee and his Generals decided to attack the Union line in the one place which had yet to be tested during the battle; in the center at Cemetary Ridge. At 1pm, the attack commenced with a Confederate artillery barrage on the Union line in an attempt to soften them for the upcoming assault. However, this barrage was unsuccessful for two major reasons.
Firstly, the Bormann fuses used by the Confederate forces were very unreliable. Unbeknownst to the artillerists, the fuses burned at wildly different rates, leading to some 80% of all shells fired missing their targets by either exploding too early, too late or sometimes not at all.
Secondly, the smoke from the Confederate cannons obstructed the view of the artillery officers, so they could not adjust their fire and simply had to trust that their shells had found their targets. So, the Confederate artillery barrage was largely ineffective.
To add to their opponent's misery, the Union gunners began to slow their own fire at 2pm in an attempt to trick the Confederates into thinking that their barrage had disabled the Federal guns. The ruse worked and at 3pm, Lee sent General Pickett and his men to attack.
12,000 troops set out across no man's land in the direction of Cemetary Ridge and, as they emerged from the smoke of their own guns, the Union artillery resumed their fire. This conflagration was lethal for Pickett's men, as they marched in tight groups which made them easy targets for the Federal gunners on Cemetary Ridge, as well as the Little Round Top.
Pickett's progress was also slowed due to the presence of a fence halfway between the Confederate and Union lines, making the Southern infantry sitting ducks. What remained of Pickett's men did reach the Federal lines on Cemetary Ridge, where the two sides engaged in bloody hand-to-hand combat. The original Confederate plan called for reserves to be sent from the rear to aid their compatriots in the struggle. However, those reinforcements never arrived. So, the last of the attackers called off the assault and retreated back to their original positions. The Confederates lost some 7,000 troops that afternoon.
General Lee expected a Union counter-attack which never materialized. So, the Confederate forces retreated from the town of Gettysburg under the cover of dark on the night of July 4, 1863. Along with the Battle of Vicksburg, fought almost simultaneously as Gettysburg, this battle is regarded as the turning point of the American Civil War, and it is also the single-bloodiest engagement of the entire conflict.
Never again would a Confederate soldier set foot on Union soil, with the war ending less than two years later with Lee's surrender to General Ulysses S Grant at Appomattox Courthouse in April 1865.

From July 1–3, 1863, the Battle of Gettysburg raged between the Union and the Confederacy in the state of Pennsylvania. After two difficult days of battle, the conclusive third day arrived. On July 3, General Robert E. Lee's Confederate troops made a final attempt to break the Union lines. Confederate general George Pickett was tasked with commanding the 15,000-man attack that would become known as "Pickett's Charge."
The assault was prefaced by a heavy artillery bombardment of the Union position by the Confederates. Following the artillery bombardment, which is considered to have been mostly ineffective, Pickett's men embarked on an assault of the Union position at Cemetery Ridge. The Confederate forces, however, had a difficult situation ahead of them. They needed to cross approximately one mile of open land before reaching the Union lines. To complicate things further, the hot summer weather forced the Confederate forces to march rather than run towards the Union position. They planned to "charge" or run only when within close range of Union lines.
While the Confederate artillery barrage was largely ineffective, the counter-artillery of the Union was very effective. As the Confederates crossed the open land in front of the Union forces, they were cut down by heavy Union cannon fire. Even when Union cannons missed the advancing Confederate troops, they often hit reserve troops in the rear. The result was devastating casualties for the Confederates.
As the Confederates came into range of the Union infantrymen defending their position on Cemetery Ridge, they suffered further casualties. Only a few hundred Confederate troops even reached the Union lines, and they were quickly cut down and turned away. In the short time between the commencement of Pickett's Charge and the retreat of Pickett's men, over 7,000 Confederate troops had been killed or wounded. On the night of July 4, Lee and his Confederate troops withdrew from the battlefield and retreated south. The Union forces, who had fought hard for three days, were unable to pursue Lee's forces.
The Battle of Gettysburg would see the most casualties of any battle during the Civil War. It would also serve as a major turning point, along with the Battle of Vicksburg, which concluded on July 4, 1863. General Lee's forces would never enter the North again, and in April of 1865 they would be forced to surrender and end the war.
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