Riker was mustered out of the regiment in 1865 as a first lieutenant.
Aaron D. Riker, Columbus, Ohio, July 27, 1865.
Riker kept a detailed journal recounting his experiences during the Civil War. The journal is now housed at the George J. Mitchell Department of Special Collections and Archives, Bowdoin College Library, Brunswick, Maine. Journal. Transcript.
Here is Riker's account of his regiment's role at the Battle of Gettysburg on Culp's Hill (edited for spelling, punctuation, and consistency). At the time, the 66th Ohio Infantry, commanded by Lieut. Col. Eugene Powell, was in the first brigade (Col. Charles Candy) of the second division (Brig. Gen. John W. Geary) of the 12th army corps (Maj. Gen. Henry W. Slocum) in the Army of the Potomac (Maj. Gen. George G. Meade).
Gettysburg, Pennsylvania, July 1863
Our army followed close on their track. Our corps crossed the river and marched to Frederick City, Maryland, thence in the direction of Gettysburg. The Rebels were evidently trying to get out of the scrape they were in and get safely back across the Potomac.
Our advance came up with them a little beyond Gettysburg, where considerable skirmishing ensued. Our advance fell back to the main body and formed in order of battle in the form of a horseshoe occupying the crest of a hill overlooking the town of Gettysburg. Our corps, the 12th, occupied the right.
The town of Gettysburg today, as seen from the observation tower atop Culp's Hill.
This was the [2nd] day of July. There had been some hard fighting today. Night coming on put an end to the battle, each army occupying good positions when the fighting ceased. Both armies slept on their arms ready to commence the work of tomorrow.
Union soldiers firing across a field in a reenactment at Spangler's Spring on the south base of Culp's Hill.
While this lull in the conflict, generals met to devise plans for the work before them. They feel the responsibility resting upon them. General Hooker has been relieved and General Meade is now in command of our army. We hope he may be successful. If not, who can foretell the consequences.
Union encampment in a reenactment at Spangler's Spring on the south base of Culp's Hill.
I cannot describe this suspense before a battle. Many of our boys went into the battle of Gettysburg very low-spirited from causes which I will explain. It was thought by us and firmly believed that the Rebels were meeting with great encouragement throughout many portions of the North and that they were aided in this, their second invasion of the North, by designing and willful coworkers in treason, who prowled throughout the homes of those who were sacrificing everything, even life, to protect these homes we held most dear.
The darkest hours of the war seemed to be just preceding the battle of Gettysburg. I have heard the weather-beaten and battle-stained hero talk of despairing in the noble cause. We dreaded not the work in our front but the cowardly incendiary who invited Rebel invasion and threatened to burn and pillage in our rear.
Could we have had all this hellish band mingled with the Rebel horde--yes, every Copperhead in the North who has dared to breathe treason through his already stinking nostrils--had once been conscious they were with all their brothers in crime, the Rebel horde, and ready to meet us on the hills of Gettysburg, we could have whipped them all combined, so intense were our feelings against this cowardly class. But we know they stood a great way off and encouraged the rebellion. They would sooner make war upon helpless women and children than to face us. I fear the historian has not yet lived who can command his pen to write the infamy with which these men are stamped.
What were the feelings of our brave men, worn veterans, upon that fateful night we leave you, reader, to guess. Here was the true and tried soldier from the Keystone State; his home had been invaded, perhaps then his wife and children were being plundered and turned from their home, an aged father or mother might even then be calling for assistance, some strong arm to succor them from the hands of a relentless foe. We knew the barbarism of our enemies, and we thought too of that class who, while they were glad to take shelter under the folds of the spotless banner of Liberty, were at the same time devising means for the overthrow of our Government secretariat and openly working into the hands of Rebels in arms against us.
The morning of the [third] of July broke at last, and the heavy booming of cannon told the work of carnage had commenced. The first gun was fired by our division at 3 a.m. The fighting became general all along our lines. The constant roar of artillery, intermingled with the roar of small arms, was beyond the power of pen to describe.
Typical artillery piece on Culp's Hill.
The slaughter was horrible. Here our loss was also heavy. On the right [Culp's Hill], our forces were so well protected by breastworks that the loss on our part was almost nothing while that portion of the field occupied by the Rebels was literally strewn with dead.
Union soldier firing over the top of a breastwork of rocks and logs, as depicted in the monument to the 78th and 102nd New York Infantries, which took part in the defense of Culp's Hill. Such breastworks were typically surmounted by a horizontal log that protected the head but left a narrow gap to aim and fire a rifle.
Monument to the 66th Ohio Volunteer Infantry, positioned where the regiment fought at the top of Culp's Hill.
I visited the portion of the field where our division had fought. The loss on our side had been very light, but one man killed in the 66th and 12 wounded; the loss in other regiments but slight. Major Palmer of the 66th was mortally wounded and died a few days after the battle.
Memorial to Major J. G. Palmer marking the location where he was mortally wounded on Culp's Hill.
The loss on the side of the enemy was horrible. The dead lay in piles, in places even up to our line of breastworks. They had fearlessly charged and were mown down by dozens by our boys. Suitable parties were detailed to collect and bury the dead, and the army pursued the fleeing enemy. The 12th corps marched back by way of Frederick City on the flank of the enemy.
Principal battles in which the 66th Ohio Volunteer Infantry fought during the Civil War, based on the list engraved on the monument dedicated to the regiment in Gettysburg: Port Republic, Cedar Mountain, Antietam, Dumfries, Chancellorsville, Gettysburg, Lookout Mountain, Missionary Ridge, Ringgold Gap, Dug Gap, Rocky Face Ridge, Resaca, New Hope Church, Pine Mountain, Kennesaw Mountain, Peachtree Creek, Atlanta, Savannah.
Photos by I. Peterson, May 2019.