The 155th Pennsylvania Volunteer Infantry Regiment lost 5 officers and 137 enlisted men killed or mortally wounded and 1 officer and 111 enlisted men to disease during the Civil War. It is honored by a monument at Gettysburg.

1862
September 2-19 Organized at Camp Copeland, Pittsburg and Harrisburg under Colonel Edward J. Allen, Lieutenant Colonel James Collard, and Major John H. Cain.
September 4 Moved by train to Washington, D.C. (the men in catle cars) and attached to 2nd Brigade, 3rd Division, 5th Army Corps, Army Potomac. Springfield muskets replaced the Austrian rifles originally issued.
September-October Moved to Sharpsburg, Md., arriving after the close of battle, and duty there
October 30-November 19 Movement to Falmouth, Va.
December 12-15
Battle of Fredericksburg

Captain Lee Anschultz was mortally wounded and the entire color guard killed or wounded in the assault on Marye’s Heights.

December 31 Lieutenant Colonel James Collard resigned; Captain Alfred L. Pearson of Company A promoted to major.
1863
January 20-24 Burnside’s 2nd Campaign, “Mud March”
February-April Duty at Falmouth, Va. Colonel Allen was absent from the regiment much of the time, sick with rheumatism.
April 27-May 6 Chancellorsville Campaign
May 1-5
Battle of Chancellorsville
May Attached to 3rd Brigade, 2nd Division. 5th Army Corps
June 11-July 24 Gettysburg Campaign
July 1-3
Battle of Gettysburg

Colonel Allen was with the regiment, though ill. It was commanded by Lieutenant Colonel John H. Cain. The 155th Pennsylvania brought 424 men to the field, losing six killed and 13 wounded, including Captain McKee of Company I.

July 5-24 Pursuit of Lee
July 21 Colonel Allen was discharged due to disability. Lt. Colonel Cain was promoted to colonel.
August-October Duty on line of the Rappahannock and Rapidan. Lieutenant Colonel Cain resigned.
October 9-22 Bristoe Campaign
October 13 Auburn
November 1 Major Pearson was promoted to Colonel and John Ewing to lieutenant colonel, and Captain J. A. Kline to major.
November 7-8 Advance to line of the Rappahannock
November 7 Rappahannock Station
November 26-December 2 Mine Run Campaign
1864
December – April Duty on Orange & Alexandria Railroad
January 19, 1864 The regiment was issued with Zouave uniforms. Brigadier General Kenner Garrard had been working since the fall of 1863 to have the regiments of his brigade learn French Zouave light infantry tactics, and rewarded them with the right to wear the uniform. It consisted of a blue Zouave jacket and matching baggy trousers, ten foot red wool flannel sash, and a tassled red fez (or turban on dress occasions). The uniforms had been adopted from French Chasseur unfiroms that had to be modified for the larger men of western Pennsylvania. The 155th wore, and apparently liked, the colorful uniform until the end of the war.
January 24 Captain Joseph B. Sackett was accidently drowned returning from the picket line.
March Attached to 4th Brigade, 1st Division, 5th Army Corps
April Attached to 1st Brigade, 1st Division, 5th Army Corps. This became known as the Zouave Brigade as each of its regiments qualified in Zouave tactics and were issued with the uniform.
May 4-June 12 Rapidan Campaign
May 5-7
Battle of the Wilderness

Captain John C. Stewart and Lieutenant Edward P. Johnston were badly wounded and eventually discharged for disability.

May 8-21
Battle of Spotsylvania Court House

Captain Edward E. Clapp and Lieutenant Charles Johnston were killed in assaults on Confederate defences at Laurel Hill.

May 8  Laurel Hill
May 12 Assault on the Salient
May 23-26 North Anna River
May 26-28 On line of the Pamunkey
May 28-31 Totopotomoy
June 1-12 Cold Harbor, attached to 1st Brigade, 2nd Division, 5th Army Corps
June 1-3 Bethesda Church
June 16-18
First Assault on Petersburg

The regiment lost 83 casualties in the space of ten minutes in an assault on Confederate defences, including Captain Samuel McKee, who was killed.

June 16, 1864 Siege of Petersburg, attached to 2nd Brigade. 2nd Division, 5th Army Corps
July Attached to 2nd Brigade, 1st Division, 5th Army Corps
July 30 Mine Explosion, Petersburg (Reserve)
August 18-21 Six Mile House, Weldon Railroad
September 29-October 2 Poplar Springs Church, Peeble’s Farm
October 27-28 Boydton Plank Road, Hatcher’s Run
December 7-12 Warren’s Raid on Weldon Railroad, attached to 3rd Brigade, 1st Division, 5th Army Corps
December 23 Colonel Person took command of the brigade, and was eventually brevetted brigadier and major general.
1865
February 5-7 Dabney’s Mills, Hatcher’s Run
March 28-April 9 Appomattox Campaign
March 29
Junction Boydton and Quaker Roads and Lewis Farm

Approaching confederate breastworks, the regiment recived a volley that killed Lieutenant James Strong and a number of enisted men. The regiment faltered, but was rallied by Brigadier General Pearson, who earned the Medal of Honor for his actions. According to the citation, “Seeing a brigade forced back by enemy, he seized his regimental color, called on his men to follow him, and advanced under a severe fire. The whole brigade took up the advance, the lost ground was regained, and the enemy was replused.”

March 31 White Oak Road
April 1
Five Forks

Lieutenant Thomas P. Dunn was killed.

April 9
Appomattox Court House

Surrender of Lee and his army.The regiment claims 17 year old William Montgomery of Company I was the last soldier killed in the Army of the Potomac. He was mortally wounded by a Rebel shell an hour before the truce. Montgomery was taken to a hospital in Farmville, Virginia, where he died on April 28.

May 1-12 Moved to Washington, D.C.
May 23 Grand Review
June 2 Mustered out