Richard Byrne (1832 – June 10, 1864) was an Irish-American officer in the United States Army, who rose to command the Irish Brigade.
Byrne was born in County Cavan, Ireland, and emigrated to New York in 1844. Five years later he enlisted in the regular army of the United States, joining the Second Cavalry, a regiment then commanded by Colonel E. V. Sumner. In this regiment young Byrne distinguished himself in the Indian campaigns in Florida and Oregon.
At the breaking out of the American Civil War he was, on the recommendation of his old commander, Colonel Sumner, commissioned First Lieutenant in the Fifth Cavalry, one of the new regiments authorized by Congress. During the campaigns of 1861 and 1862 he remained with the regiment of regulars and was then appointed by Governor John Albion Andrew, Colonel of the Twenty-Eighth Massachusetts Volunteers, an Irish regiment of which he took command, October 18, 1862. In the November following, this regiment was attached to Thomas Francis Meagher's Irish Brigade and with it participated in all the fierce fighting in which the Army of the Potomac was subsequently engaged.
At its head Colonel Byrne charged up the slope of Marye's Heights at the battle of Fredericksburg, and after it, like the other regiments of the brigade, had been almost wiped out in the sanguinary conflicts at Chancellorsville and Gettysburg, he was sent back to Massachusetts to recruit its ranks during the winter and spring of 1863 and 1864. When the campaign reopened in May he returned to the front and as the senior officer took command of the Irish Brigade.
Two weeks after assuming command, on June 3, 1864, he fell, mortally wounded, while leading the brigade at the attack on the entrenchments at Cold Harbor, Virginia. He lived long enough to be conveyed to Washington, where his wife reached him before he died. His commission as brigadier general had just been made out by President Abraham Lincoln, but he was dead before it could be officially presented to him. His remains were sent to New York and buried in Calvary Cemetery.
- Conyngham, The Irish Brigade and its Campaigns (Boston, 1869);
- The Emerald, files (New York, January 8, 1870).