An Irish regiment, whose gallant service on many fields attested the off-acknowledged valor of the Irish soldier. Though organized in April, 1861, it did not reach Washington until June 29th. After a months' stay in the vicinity of the Capitol, it crossed into Virginia and encamped on Arlington Heights, remaining there until March, 1862, when it went to the Peninsula. Its first battle occurred at Hanover Court House, although it participated in the Siege of Yorktown. It was assigned to Griffin's (2d) Brigade, Morell's (1st) Division, Fifth Corps, a division famous for the prominent part taken by it at Gaines's Mill and Malvern Hill. The Ninth distinguished itself at Gaines's Mill by the steadiness with which it sustained a heavy attack, its losses that day amounting to 57 killed, 149 wounded, and 25 missing; total, 231; six line officers were killed there, and four days later the Colonel fell, mortally wounded, at Malvern Hill. The regiment was engaged at Gettysburg as skirmishers, hence their slight loss in that battle. While on Grant's campaign, in 1864, the brigade was commanded by Colonel Sweitzer, and the division by General Griffin. The losses of the regiment at the Wilderness were 26 killed, 108 wounded, and 3 missing; and at Spotsylvania, 25 killed, 71 wounded, and 9 missing. During the entire period of its active service it was in the Second Brigade, First Division, Fifth Corps. It was relieved from duty June 10, 1864, and ordered home for muster-out.