This regiment, recruited in Delaware county, was organized at Delhi, and there mustered into the U. S. service on Sept. 27, 1862. It left the state on Oct. 11, 956 strong, and was stationed in the defenses of Washington at Upton's hill, Cloud's mills and Vienna until April, 1863. It was then assigned to the Department of Virginia, and in Gurney's division assisted in the defense of Suffolk during Longstreet's siege of that place. In May it was placed in Gordon's division of the 7th corps at West Point, and shared in the demonstration against Richmond. In July it joined the 2nd brigade, 1st (Schimmelfennig's) division, 11th corps. This division was detached from its corps on Aug. 7, and ordered to Charleston harbor, where during the fall and winter of 1863 the regiment was engaged at Folly and Morris islands, participating with Gillmore's forces in the siege of Fort Wagner and the bombardment of Fort Sumter and Charleston.
In Feb., 1864, in the 1st brigade, Ames' division, 10th corps, it was engaged at Seabrook and John's islands, S. C. It was then ordered to Florida, where it was chiefly engaged in raiding expeditions and was active in the action at Camp Finnegan. It returned to Hilton Head in June; was active at John's island in July, losing 13 killed, wounded and missing; in Potter's brigade of the Coast division it participated in the cooperative movements with Sherman, fighting at Honey Hill and Deveaux neck. Its casualties at Honey Hill were 108 and at Deveaux neck, 37 killed, wounded and missing. Lieut. James W. Mack the only commissioned officer killed in action, fell at Honey Hill. Attached to the 3d separate brigade, District of Hilton Head, it was severely engaged at James island in Feb., 1865, losing 44 killed, wounded and missing. In the fall of 1864 the ranks of the regiment were reduced to between 300 and 400 men through battle and disease, and it was then recruited to normal standard by one year recruits from its home county. The regiment was mustered out at Hilton Head, S. C., June 25, 1865, under command of Col. Lewis. It lost by death during service 40 officers and men, killed and mortally wounded; 4 officers and 174 enlisted men died of disease and other causes; total, 218.
Source: The Union Army, Vol. 2, p. 153; Phisterer, p. 3,667
30 Jul 1863 at Goose Creek, VA.
15 Aug 1863 at Morris Island, SC.
25 Aug 1863 at Fort Wagner, SC.
9 Jul 1864 at John's Island, SC.
30 Nov 1864 at Honey Hill, SC.
9 Dec 1864 at Deveaux's Neck, SC.
10 Feb 1865 at James Island, SC.