The Army Of The Potomac

164th New York Volunteer Infantry

As the Union's field armies grew in size, various of their commanders attempted to make units easy to identify in the field through systems of unique flags carried by each formation and unit. The Army of the Potomac's General Orders No. 102 was issued 24 March 1862, under Major-General George B. McClellan's direction, and gave the Union Army its first comprehensive army-wide flag designating system. According to the sections which provided instructions on flags, the army's general headquarters...