On September 6, 1862, Stonewall Jackson occupied Frederick, Maryland. A short excerpt from the article:
"The architect of the Confederate victories in the east, General Robert E. Lee, sought to exploit the opportunity his victory at Second Manassas offered. Lee understood from the beginning of the war that the Confederacy’s best hope for independence rested upon the morale of the Northern people. If they believed the war could not be won, or could only be won at too high a cost, then Southern independence became a real possibility. Confederate military successes were the means to erode morale and create this political climate. The fall elections in the North were approaching. England and France stood on the sidelines watching closely, carefully weighing whether they should recognize the Confederacy. Lee sensed a great opportunity was at hand. He believed the Union army was disorganized and demoralized. He also knew that it was receiving many reinforcements in the form of newly raised regiments in answer to President Lincoln’s July call for 300,000 volunteers. Only one move would force the Federals to place their army in the field before they had reorganized and offered the best chance to do further damage to Northern morale: Invade the border state of Maryland."