They finally crossed the Mason-Dixon line in June 1863 - following an earlier attempt in September 1862.
The Confederates.
The Confederates were hoping to inflict enough casualties on the North to demoralize them and sway public opinion in the North against the war. In this way, the North would decide that it just wasn't worth it, and allow the Confederacy to remain independent from the rest of the United States, which was just what they wanted.
The Union in the north and the Confederates in the South.
States in the south that fought with the north during the Civil War. The Confederates wanted slavery, but the Union, or the North, was against it.
The Union of the North, and the Confederates of the South fought in the US Civil War.
Gettysburg
Because the Confederates never managed to invade the North, except briefly at Gettysburg.
Gettysburg and Vicksburg was important because it showed that the Confederates could not invade the North.
To convince the British that the Confederates had a good chance of winning, and were worth backing.
The Allies never invaded North America. They did invade North Africa with Operation Torch in November 1942.
1944
For the Confederates, it was the nosedive moment. Overnight, the West was out of the war, and Lee had failed to invade the North.
Credibility as a new nation, and possibly gaining recognition abroad, by showing that they were substantial enough to invade the North instead of just defending the South.
Hitler did not invade North Korea.
The Confederates
The Union won the Battle of Gettysburg. Lee retreated to Virginia. Meade failed to vigorously pursue, and the war continued for another year and nine months.The Confederates would never again try to invade the North and threaten Washington DC.
Unfavourable. It had suffered a string of defeats by Lee, who appeared to be keeping up his momentum. Now he was planning to invade the North, and if he succeeded, Britain and France were poised to send aid to the Confederates.