As corporal of the guard on board the U.S.S. Wabash during the assault on Fort Fisher, 15 January 1865. As one of 200 marines assembled to hold a line of entrenchments in the rear of the fort which the enemy threatened to attack in force following a retreat in panic by more than two-thirds of the assaulting ground forces, Cpl. Tomlin took position in line and remained until morning when relief troops arrived from the fort. When one of his comrades was struck down by enemy fire, he unhesitatingly advanced under a withering fire of musketry into an open plain close to the fort and assisted the wounded man to a place of safety.