On June 15, 1863, the third summer of the US Civil War, General Robert E. Lee’s Army of Northern Virginia crosses the Potomac and begins an invasion of the North. This army consists of 70,000 men, most of whom are unpaid and self-equipped. They have a unique sense of unity and have a strong faith in their commanding general as well as their fighting ability, as they have often been victorious against the superior numbers of the Union Army. Using the Blue Ridge to shield their movements, the army hopes to bring the Union Army into the open. By the end of the month, the Rebels are closing on Harrisburg, Pennsylvania.

The Army of the Potomac, on the other hand, is moving slowly, eventually turning north in pursuit of Lee’s army. This army of 80,000 is a conglomeration of a wide variety of men fighting for the Union, with varying backgrounds, languages, and religions. This army is accustomed to defeat and changing commanders, causing it to lose faith in its leaders but not itself. The army knows a battle is coming and thinks it will be the last. The soldiers are grateful to fight on their home ground.