The Gettysburg Campaign began as Confederate General Robert E. Lee prepared to march his Army of Northern Virginia into Pennsylvania. This represented Lee's second invasion of the North after the previous attempt at the Battle of Antietam in 1862. The motivation behind this campaign was multifaceted. Lee sought to relieve the stress on Virginia's resources, bolster the morale of the Confederate states, and possibly influence the Northern public sentiment in favor of peace through a significant victory. Lee's forces, consisting of approximately 75,000 soldiers, were met with a mix of fear and anticipation as they crossed into Union territory. The Army of Northern Virginia included many experienced and battle-hardened troops who had achieved notable successes in previous engagements, bolstering their confidence.

The campaign was notable for its movement through Maryland and Pennsylvania, with Lee hoping to connect with local sympathizers and disrupt Union supply lines. His soldiers traveled through various towns, with the townspeople often reacting with a mix of respect and dread towards Lee’s army. The Confederate march set the stage for the future encounter between Union and Confederate forces at Gettysburg, which would become one of the most significant battles of the American Civil War. The movement and strategy behind this campaign were crucial in shaping the conflict's trajectory over the following weeks.