In the early days of the Civil War, loss after loss dogged Union forces in the east. By the end of the summer of 1862 Confederate General Robert E. Lee, emboldened by his successes, launched an invasion into the North, hoping to force a settlement that would recognize the Confederacy. The events that followed are known today as the Maryland Campaign of 1862. This work describes in detail the role played by Framingham?s General George H. Gordon, and his brigade (3rd. Brigade, 1st Division, 12th Corps, Army of the Potomac) in that campaign, and more specifically in the battle of Antietam. This was the bloodiest single day of that war.