Murphy served in the
Union Army during the
American Civil War. In the Summer of 1861, he enrolled in a volunteer company from
Brown County known as the "De Pere Rifles", which was mustered into service as Company F of the
14th Wisconsin Infantry Regiment. He received the
Medal of Honor for his actions during the
Second Battle of Corinth, where he continued carrying his regiment's
colors despite being wounded three times. He was also wounded in the
Battle of Shiloh and
Battle of Iuka. Murphy had one final stint in the Union Army, when he was commissioned 1st lieutenant of Company D,
53rd Wisconsin Infantry Regiment in April 1865. Only four companies of the 53rd Wisconsin Infantry were organized, but the regiment was never officially mustered into federal service, as the bulk of Confederate forces had surrendered by this time. Nevertheless, the four companies had been dispatched to
Leavenworth, Kansas. They were subsequently consolidated into the
51st Wisconsin Infantry Regiment. Murphy's Company D became Company I of the 51st Wisconsin Infantry. The 51st Wisconsin Infantry returned to Wisconsin in August and was mustered out of service. ==Postbellum years==