The following is taken from New York in the War of the Rebellion, 3rd ed. Frederick Phisterer. Albany: J. B. Lyon Company, 1912.

This battalion, consisting originally of four companies, was recruited in New York city between September and December 9, 1861, and there mustered in the service of the United States for three years, December 9, 1861. The original plan was to raise an artillery company for each of the four regiments of the Irish, or Meagher's, Brigade. The battalion left the State December 16, 1861, commanded by Maj. Thomas O'Neill. The companies were commanded: A, by Capt. Henry J. McMahon; B, by Capt. Wm. H, Hogan; C, by Capt. Michael Mitchell; and D, by Capt. Wm. O'Donohue. On their arrival in Washington, D. C., the companies, not having been recruited to the artillery standard, were, about December 21, 1861, consolidated into two companies; B and D forming new Company A, and A and C new Company B. The battalion organization was discontinued in October, 1862, and the companies designated the 14th and 15th Batteries of Light Artillery.

The losses, services and engagements of the battalion are incorporated in the record of the 14th and15th Batteries; except the loss of one field officer, died of an accident before discontinuance of the battalion.

The following is taken from The Union army: a history of military affairs in the loyal states, 1861-65 -- records of the regiments in the Union army -- cyclopedia of battles -- memoirs of commanders and soldiers, Volume II: New York, Maryland, West Virginia and Ohio. Madison, WI: Federal Pub. Co., 1908.

Second Battalion Light Artillery.—Maj., Thomas O'Neill; Capts., William H. Hogan, Michael Mitchell, Henry J. McMahon, William O'Donoghue. This battalion, known as the Irish Brigade batteries, originally consisted of four batteries and was recruited in the fall of 1861, in New York City, where it was mustered into the U. S. service for three years on Dec. 9. The first plan was to raise an artillery company for each of the four regiments of the brigade. The battalion left the state on Dec. 16, and on reaching Washington was consolidated into two batteries, designated A and B. In Oct., 1862, the battalion organization was discontinued. Battery A being constituted the 14th and Battery B, the 15th independent batteries. Fourteenth Independent Battery.—Capts., William H. Hogan, James McKay Rorty. The battery served with Richardson's division, 2nd corps from March to May 26, 1862, when the first section was attached to Battery C, 4th U. S. artillery; the second to Battery G, and the third to Battery B, 1st N. Y. artillery. On Jan. 16, 1863, the first section was transferred to Battery G, 1st N. Y., and in September these transfers were made permanent by order of the war department, the battery being discontinued. The battery took part in the siege of Yorktown, the Seven Days' battles, Antietam, Leesburg, Charlestown, Snicker's gap, Fredericksburg, Chancellorsville and Gettysburg. It lost during service 2 officers and 3 men killed and mortally wounded, and 4 men died of disease. Fifteenth Independent Battery.—Capts., Henry J. McMahon, Patrick Hart. One officer and 18 men were transferred to this battery from the 4th in Dec. 1863. On the expiration of its term of service the original members (except veterans) were mustered out, and the veterans and recruits consolidated with the 32nd battery on Feb. 4. 1865. The 15th took part in the engagements at Chancellorsville, Gettysburg, Rappahannock Station, the Mine Run campaign, Wilderness, Spottsylvania, the North Anna, Totopotomy, Cold Harbor, first assault on Petersburg and the Weldon railroad. It was before Petersburg from June to Nov., 1864, when it was withdrawn from the front and returned to Washington, serving in the 22nd corps and the Department of West Virginia during the winter of 1864-65. It lost during service 9 men killed in action and 3 men from disease and other causes.