2. Shaw was commissioned as an officer in the 2nd Massachusetts infantry in 1861
In May, 1861, Robert Gould Shaw was commissioned as a lieutenant in the newly formed 2nd Massachusetts Infantry Regiment, commanded by Colonel George Gordon. Shaw finally found the adventure he had long sought with the regiment, which was active in the Potomac region in Maryland and Virginia, and in the Shenandoah Campaign in early 1862, where it was outmaneuvered and outfought by Confederate troops under Stonewall Jackson. In the late summer of 1862, it was part of the Army under George McClellan, which faced the Confederate Army of Northern Virginia under Robert E. Lee at the Battle of Antietam.
The Battle of Antietam was then and remains today the bloodiest single-day combat of American history. Shaw was in the thick of the fighting as his unit attempted to advance upon fortified Confederate positions through a cornfield. It was some of the worst fighting of that day of violence and slaughter. Shaw, by then a captain, was wounded in the morning advance, and remained on the battlefield until the fighting was over. He was sent home to recuperate from the wound to his throat, and thus missed the slaughter encountered by his regiment in engagements at Chancellorsville and Gettysburg the following year.