The battle of Gettysburg took place from July 1–3, 1863 and was a major combat in the American Civil War. The battlefield was 35 miles southwest of Harrisburg, Pennsylvania. General Robert Edward Lee decided to attack the North hoping to discourage the opponent even more, after defeating the Union forces of General Joseph Hooker at Chancellorsville, Virginia, in May.
Lee had troops under him amounting to 75,000 men. When General Lee found out that the Union Army of the Potomac had a new commander, General George Gordon Meade, he ordered General Ewell to go to Cashtown or Gettysburg. Meade’s commander General John Buford realized the importance of Gettysburg as far as strategy is concerned; due to the fact that Gettysburg was a road center. Heavy casualties on each side were suffered on the first day of the battle and on the second day both sides had to suffer even more losses. On the third day, when Lee was determined to attack, the events of these days got the famous name “Pickets Charge”, owing to the fact that about 15,000 Confederate soldiers, who were led by General George Edward Pickett, were held by about 10,000 Federal infantrymen. The Southerners retreated that day. Although Meade did not destroy the opponent, he had at least stopped the Confederate invasion and won the battle which lasting for three days.
However, severe casualties had been suffered on both sides again. The Northern troops lost about 3,100 of their 88,000 men; and the Southern force lost approximately more than 4,500.
In 1895, the battlefield became a national military park.
The link below provides additional information about the battle of Gettyburg:
http://www.britannica.com/EBchecked/topic/232210/Battle-of-Gettysburg
General George Gordon Meade