Member of the Irish Volunteers of Charleston. He took part in the following important engagements; Fort Sumter, Jefferson Springs, Manassas, Ox Hill, Harper's Ferry, Sharpsburg, Butler's Ford, Fredericksburg, Gettysburg, Mine Run, Liberty Mills Wilderness, Spottsylvania, Jericho Ford, Turkey Ridge, Petersburg, Riddle's Shop, Steam Station, Ream's Station, Deep Bottom, Tuzzle's Mill, Jones Farm, White Oak Road and Sutherland Station. He enlisted in the states service on December 27, 1860, as a second sergeant in the First Rifles, South Carolina Militia. He entered the service of the Confederate states in June, 1861, with Company K, First South Carolina Volunteers, Gregg's Regiment. On January 23, 1862, he was commissioned a first lieutenant and June 2, 1861, a captain, which rank he held at the end of hostilities. Of the valor and chivalry of southern officer and men Colonel Armstrong delighted to tell. Of his own services he said little. Others, however, have told something of his courage, of his genial wit which even in pain and danger did not desert him. First, of course is the high praise of General Robert E. Lee, "As brave a soldier, ladies, as ever fought in the Army of Northern Virginia." Only a few weeks before Captain Armstrong had been appointed a colonel on the staff of the new governor, Wade Hampton, a fact to which Colonel Edward McCrady, the historian of South Carlina and Colonel Armstrong's immediate commander, alluded in his address. At Gettysburg, Colonel McCrady said "when in the absence of Sergeant Spellman from wounds, Sergeant Larkin, who was worthily bearing the colors, was shot down as the regiment was crossing the stone wall in front of the town. Captain Armstrong lifted and holding them aloft charged with them at the head of the regiment. Led by Generals Pender and Perrin the regiment pressed on, and these old colors, which had come from Fort Sumter, were planted in the center of the town of Gettysburg, and there aligned on them was the color company--Company K, the Irish Volunteers. Of Colonel Armstrong, whose services I rejoice that his excellency the governor has recognized by calling him to his staff, it is not necessary for me to say much before this assembly, but let me remind you of some remarkable facts in his career. He was with the very first troops that took the field on the December 27, 1860, and was wounded and captured in the very last fight of the war, and was the last Confederate soldier discharged from the federal hospital in Washington. He was four times severely wounded, and has given to the Irish Volunteers the honor of having furnished the man who was the first in and the last out of the war.

Taken partially from the News & Courier August 16, 1930.