Tappen would serve in several New York Regiments during his service. Initially he would be commissioned a captain with the 20th New York Infantry in April, 1861. A 3 month regiment, they would serve in Annapolis and Baltimore before being mustered out of service that August. Two months later, Tappen would be commissioned a captain with the 80th New York Infantry in early October. The following August he would discharged for a promotion and join the 120th New York Infantry taking a major’s commission. It was in this role that he would see his first major engagement, taking part in the Second Battle of Bull Run. While fighting during the engagement, Tappen would receive a head wound. He would survive the wounding and in February he would take command of the regiment following the absence of Colonel Westbrook. They would fight at Chancellorsville and Gettysburg where Major Tappen would command the regiment again following Westbrook’s wounding. They would take 204 casualties during the fight. In February of 1864 he would be promoted to lieutenant colonel and lead the regiment at such places as the Wilderness, Spotsylvania, Cold Harbor and several others engagements before being discharge in December, 1864. Tappen is shown here striking this casual pose while serving as captain with the 80th New York. An ink inscription across the front bottom reads “J. R. Tappen Cap. Co. C.”. No back mark on this one.