In 1854 Mr. Mudd moved to St. Louis, where he established an extensive mercantile business as well as a reputation for integrity and public spirit. In 1859, he moved with his family and business to Chicago, where, shortly after the outbreak of the war, he enlisted as a member of the Second Illinois Cavalry, and on September 23rd, 1861, received his commission as Second Major.
Major Mudd was stationed for a time at Paducah, Kentucky, and participated in the subsequent campaigns in Kentucky, Tennessee and Mississippi.
Immediately after the surrender of Fort Donelson, Major Mudd was informed that a man had just left with important papers. Mudd followed in the hope of overtaking the man, and in doing so, passed beyond the Federal lines. He had gone but a short distance when he met a citizen who asked for protection, which was granted. As the two were riding towards Dover, they were joined by two others who also asked for protection. While engaged in conversation with them the first one fell in the rear, drew his revolver and fired at the Major. The bullet struck near the spine but the wound was not fatal. The Major immediately put spurs to his horse, when the man fired a second time but without effect, and then fled.
Upon his way to our lines, the Major, while suffering intensely from his wound and weak from the loss of blood, captured a rebel officer and, being loath to risk further bullets in the back, compelled him to ride into camp in advance.
Owing to the confusion following the surrender of the fort, the Major had much difficulty in finding a surgeon to examine and dress his wound. It was decided not to extract the bullet, and he carried it until his death. The wound healed slowly and he never fully recovered from its effects.
After a short leave of absence, the Major was ordered on detached service upon the staff of General McClernand, where he remained until that officer was relieved from his command at the surrender of Vicksburg.
Major Mudd participated in the operations at the siege of Corinth; and during the following winter was with his regiment in that neighborhood. At the battle of Holly Springs, after the cowardly surrender of the place by Colonel Murphy, he not only refused to surrender, but, with a small detachment of his men, cut his way through the rebel lines by which the post had been surrounded, and escaped. His conduct upon that occasion won the respect and admiration of his men. His fighting spirit was shown by capturing a considerable number of prisoners while his own detachment was escaping from a large pursuing body.
On December 31st, 1862, Major Mudd was promoted to the position of Lieutenant Colonel, to fill the vacancy formed by the resignation of Lieutenant Quincy McNeil; and a few weeks later, when Colonel Noble was mustered out of the service, he was promoted to fill the latter's position.
Colonel Mudd was actively engaged in the Vicksburg campaign and participated in every battle from Port Gibson to that of Black River Bridge.
During the siege of Vicksburg, his command was engaged in guarding the rear to prevent an attack by Johnson. Shortly before the surrender, while reconnoitering in the Black River swamp, he was shot by one of the enemy from a concealed position. One bullet struck below the left eye and lodged near the ear, while another struck near the collar-bone and passed nearly out through the shoulder. His aides supported him upon his horse and enabled him to escape capture. He bled profusely and suffered much but retained consciousness and sufficient strength to permit his removal to a place of safety at the house of a widow who did all in her power to render him comfortable until the arrival of a surgeon. He was sent to his home, where he soon recovered and again reported for duty at New Orleans, where his command was then stationed.