Civil War Congressional Medal of Honor Recipient. He served during the Civil War as a 1st Lieutenant in Company C, 13th Illinois Volunteer Infantry. He was awarded the CMOH for his bravery at the Battel of Missionary Ridge, Tennessee, on November 25, 1863. His citation reads "While commanding his company, deployed as skirmishers, came upon a large body of the enemy, taking a number of them prisoner. Lt. Josselyn himself shot their color bearer, seized the colors and brought them back to his regiment". His Medal was awarded to hom on April 4, 1898.