By the time the Irish Brigade reached the battlefield at Gettysburg, Pa., on July 2, 1863, it was a veteran unit.

The first regiment of the brigade to be formed was the 69th New York State Militia, which fought at Henry House Hill in the First Battle of Bull Run on July 21, 1861. The regiment fought bravely but was eventually pushed off the hill with 195 casualties, including 95 captured or missing, including its commander, Col. Michael Corcoran, who was wounded and captured. The 69th New York need not have fought at Bull Run at all; its term of enlistment had ended before the battle.

The early campaigns

The Irish Brigade, formally the 2nd Brigade, 1st Division, 2nd Corps, was organized in February 1862 and consisted of the 63rd, 69th and 88th New York and the 29th Massachusetts regiments. The brigade was formed and commanded by Brig. Gen. Thomas Francis Meagher and fought in Maj. Gen. George B. McClellan's Peninsula Campaign and in the Seven Days Battles near Richmond, Va.

In September 1862, the Irish Brigade fought at South Mountain and at Bloody Lane in the Battle of Antietam.

By the fall of 1862, the 28th Massachusetts and the 116th Pennsylvania regiments were added to the brigade and the 29th Massachusetts was removed. With these new regiments, the Irish Brigade distinguished itself in Maj. Gen. Ambrose E. Burnside's campaign at Fredericksburg, Va., leading the costly assault against Marye's Heights.

On May 3, 1863, the brigade was again in the thick of battle in Maj. Gen. Joseph Hooker's attack on Chancellorsville, Va., where it was posted near the Chancellor House.

At Gettysburg, the brigade was commanded by Col. Patrick Kelly, Meagher being sick with pneumonia.

Although by the time of Gettysburg the brigade had been reinforced by the 28th Massachusetts and the 116th Pennsylvania regiments, only the 28th Massachusetts fought as a regiment at the Wheatfield.

The 116th Pennsylvania was represented by four companies and other regiments by two companies each because the policy in the North was to recruit new regiments and allow older, veteran units to take their casualties and wither away.

Reduced by casualties

By November 1863, the Irish Brigade had participated in the pursuit of the Confederates across the Potomac, ending at the entrenchments at Mine Run along the Rappahannock River, where the brigade took part in a hand-to-hand struggle to drive the Confederates from their works.

"By the middle of 1864, the brigade had been reduced to nearly regimental strength. The Irish Brigade was disbanded in June 1864 when the New York regiments were consolidated into the 3rd Brigade, 1st Division, 2nd Army Corps," according to Steven J. Wright in The Irish Brigade, published in 1992.

The last fighting of the original Irish Brigade occurred in the Overland Campaign of 1864, when the brigade under Col. Thomas A. Smyth and later under Col. Richard Byrnes fought from the Wilderness to Cold Harbor, Va.

A second Irish Brigade was formed later in 1864 when the remnant of the 7th New York Heavy Artillery joined the 28th Massachusetts and the 63rd, 69th and 88th New York regiments, according to Wright. In early 1865, the 4th New York Heavy Artillery replaced the 7th New York Heavy Artillery.

The new Irish Brigade, commanded by Col. Robert Nugent, served at Petersburg, Va., and was present for the Confederate surrender at Appomattox Courthouse, Va., at the end of the war.