Constituted 1 June 1821 in the Regular Army as the 4th Regiment of Artillery and organized from new and existing units with headquarters at Pensacola, Florida.
Twelve batteries of the regiment served in the American Civil War. Battery B was part of the Union Army's crack Iron Brigade in the Army of the Potomac.
1862. Sumner's Division, Army of the Potomac, to March 1862. Artillery, 1st Division, II Corps, Army of the Potomac, to November 1862. Reserve Artillery, II Corps, to May 1863. Artillery Brigade, II Corps, to July 1863. 1st Brigade, Horse Artillery, Army of the Potomac, to June 1864. 1st Brigade, Hardin's Division, XXII Corps, to July 1864. Camp Barry, Defenses of Washington, D.C., XXII Corps, to August 1865.