Part of the famed Philadelphia Brigade, this all-volunteer regiment played a key role defending against Pickett's Charge during the Battle of Gettysburg.

A native of Derry, Ireland who was operating a saloon in Philadelphia at the start of the American Civil War, he had a reputation as a stern disciplinarian.

[11] On September 24, the regiment served as part of the Union force commanded by General William Farrar Smith during reconnoissance activities at Lewinsville, which resulted in one member of the 69th being wounded during a brief fight with Confederate troops.

[12] Ordered to Conrad's Ferry on October 20, members of the 69th then engaged in their first major combat experience during the Battle of Ball's Bluff the next day.

They made an attempt with the 69th New York to form an Irish Brigade, but Governor Andrew Gregg Curtin of Pennsylvania opposed the idea, which led to the proposal being dropped.

The 69th served in the Peninsula Campaign, during which it was complimented by Maj. Gen. Joseph Hooker for making “the first successful bayonet charge of the war.”[14] On June 30, the 69th Pennsylvania found itself in the heat of battle when Confederate troops attacked the rear of the combined Union forces "on the heights east of the White Oak Swamp."

[18] On November 4, 1862, Harrisburg's Pennsylvania Telegraph carried the front-page news that court martial proceedings overseen by Brigadier General W. S. Hancock had found the 69th Pennsylvania's commanding officer, Colonel Owen, "guilty of charge of 'conduct prejudicial to good order and military discipline, and unbecoming an officer and a gentleman.'"

'In this—that Col. J. T. Owen, 69th Pennsylvania volunteers, was much under the influence of liquor on or about the afternoon or evening of the 4th of October 1862, at or near Harper's Ferry, Virginia, and very abusive of his Lieutenant Colonel O'Kane, cursing and calling him names.'

This recommendation is supported by testimony of the highest character, adduced upon the trial, showing that the accused has been a zealous and obedient officer, and has displayed great gallantry and good conduct on the field of battle.

The general commanding trusts that the deep humiliation which the events themselves and the publicity of these proceedings must cause the accused will prevent the leniency here extended from producing any injurious influence in the service.

"In December 1862, the regiment sustained heavy casualties in the Battle of Fredericksburg, but then missed any major action at Chancellorsville, seeing only minor skirmishing.

The 69th finished the campaign under the command of Captain William Davis of Co K.[28] In January and February 1864, multiple members of the 69th Pennsylvania were transferred to the Invalid Corps by orders of the Adjutant General's Office.

The 69th participated in the pursuit of the Army of Northern Virginia during the Appomattox Campaign,[34] during which time it sustained multiple additional casualties.

[36] The 69th Pennsylvania Volunteers' first battle flag, the First State Color, was manufactured by Horstmann Brothers and Company, and was presented to the regiment sometime after November 1861.

Over 50 veterans of the 69th Pennsylvania were buried in Cathedral Cemetery in West Philadelphia, many in unmarked graves because their families were too poor to afford headstones.

[43] On Veterans Day in 2002, a memorial to the members of the regiment was installed in Cathedral Cemetery by an American Civil War reenactment group from Bucks County, Pennsylvania.

[46][47][48] The 69th Pennsylvania Irish Volunteers,[49] schools,[50] and other living history groups portray the regiment at various reenactments each year.