“For God’s sake, come and help us out…!” begged the new head of Hartsuff’s Brigade and without a pause, Colonel Lyle had the 90th Pennsylvania marching forward into the swirling inferno of Antietam’s Cornfield.
The 90th Pennsylvania Infantry Regiment was recruited exclusively within the city of Philadelphia. Originally designated the 2nd Regiment/First Brigade/First Division for three months’ service in the Pennsylvania Militia, on September 3rd 1861 the War Department formally accepted the regiment into federal service and it was this act that changed its designation to the 90th Pennsylvania Infantry, which it would carry throughout its service. Organizing and training at Camp McClellan at Oxford Park—three miles north of Frankford, Pennsylvania—Colonel Peter Lyle (who had commanded during the unit’s three months’ service) was appointed commander, aided by Lieutenant Colonel William A. Leech and Major Alfred J. Sellers. Like their commander, many of the officers and men already had military experience from serving in the prewar militia. 
The 90th Pennsylvania boys were particularly proud of their unique chasseur uniform. It consisted of a dark blue habit veste with white trimming, baggy sky blue trousers, and a dark blue kepi. Even more unusual were the specially-designed 90th PA buttons on the habit veste – the only Union regiment during the war to have their own specifically-designed regimental button.
The 900 men of the 90th Pennsylvania departed Philadelphia on the evening of the 31st of March, 1862, proceeding to Baltimore’s Patterson Park Barracks. There the men received their arms – old, converted smooth-bore muskets (which nonetheless were used until July, 1864 when they finally received more modern guns). Three weeks later the regiment was ordered to Washington, where it was assigned to serve in Ricketts’ Second Brigade, Ord’s Second Division, of McDowell’s Department of the Rappahannock. 
Departing Washington for Aquia Creek Landing, for several months the 90th served in garrison duty there and in repairing railroad lines in the Fredericksburg area. In May the regiment was sent along with the rest of Ricketts’ Division to the Shenandoah Valley, part of the force directed to stop Stonewall Jackson’s Confederate force operating there. Guarding Piedmont Station and Front Royal, the regiment marched over a lot of ground but still hadn’t seen any combat. One important development that occurred during its time in the Valley was that when General Ricketts was elevated to division command, Colonel William H. Christian of the 26th New York assumed command of the brigade to which the 90th was assigned. It was a command change that was to have a major impact on the regiment during their time in Antietam’s Cornfield.
On June 18th, the 90th headed to Manassas Junction and was assigned to Pope’s Army of Virginia, serving in Bank’s III Corps. On August 9th, the regiment took part in the battle at Cedar Mountain, but because it remained in support and suffered no casualties the 90th still hadn’t “seen the elephant.” That moment wasn’t long in coming, though because on August 28th, the 90th Pennsylvania marched into Thoroughfare Gap to participate in the ultimately unsuccessful battle there to block Longstreet’s Command from joining with Jackson, which would occur the following day at Manassas. 
Falling back on the 29th to Groveton on the old Manassas battlefield, the regiment stood there in line of battle during the day. Early on August 30th, the 90th Pennsylvania was in position to participate in Pope’s planned attack when Longstreet’s Command suddenly struck Pope’s left. General Tower, who led the brigade in place of a “sun stroked” Colonel Christian, was badly wounded and carried from the field, joining nearly 200 men of the 90th Pennsylvania who fell at Second Manassas. Falling back to Centreville, the 90th men had seen their first real combat and had proven themselves, despite their heavy losses – which were just the beginning of their sacrifice in this war.
Retiring further toward Washington, the regiment participated in the Battle of Chantilly by relieving the 21st New York in the midst of a furious rainstorm and on the next day, Major Sellers and Adjutant Weaver of the 90th received the body of General Kearny, who had fallen at Chantilly. The regiment remained in the Washington defenses until September 6th, when along with its brigade and division it was reassigned to General Hooker’s I Corps of the Army of the Potomac and headed north to Maryland in search of Lee’s army.
At South Mountain, the 90th took part in Hooker’s stalemated effort to break through Turner’s Gap. Resting on the mountain’s slopes the night of September 14th, the next day it pushed cautiously westward toward Sharpsburg. Turning north from the Boonsboro Pike, the men of the 90th Pennsylvania crossed Antietam Creek late on the 16th and pressed on westward. In early morning, the skirmishing of the previous night erupted into a full blown battle. 
Hooker’s plan was to have two of his three divisions strike at the Confederate line at the Dunker church; Ricketts division would attack through Miller’s cornfield and the East Woods, while Doubleday’s division would drive at the same target along the Hagerstown Pike. But before this could happen it became clear that Rebels deployed south of the Cornfield would have to be cleared to open the path to the church. Ricketts’ attack plan for hitting this unexpected obstacle had Duryee’s and Hartsuff’s brigades driving straight at them through the Cornfield, while Christian’s brigade—including the 90th Pennsylvania—would swing through the East Woods to join the attack by striking from the flank.
The attack, however, went awry before it even got underway. Duryee’s brigade started forward as planned but that was about all that went so. General Hartsuff was wounded and the command confusion created by this development left his brigade glued in place and Duryee to advance alone. Although Colonel Richard Coulter would eventually take charge of Hartsuff’s former unit and advance to Duryee’s aid, the damage was done. Worse, though, was that Christian’s brigade was similarly taken out of the attack because of its commander. But Colonel Christian’s wound wasn’t physical damage, but rather a mental and emotional breakdown that had him fleeing in panic from the field, leaving the 90th regiment and the rest of his brigade immobile and mired in confusion.
At this same moment, Hartsuff’s brigade—which had replaced Duryee’s battered command before two Rebel brigades, keeping alive Hooker’s attack through the Cornfield—was nearing the end of its rope. Casualties were mounting rapidly and yet no help appeared, including from nearby Christian’s brigade – which remained stalled by its command vacuum. Colonel Coulter had raced up to Colonel Christian only moments before begging “For God’s sake, come and help us out…” The plea had force Colonel Christian’s hand and prompted the brigade commander to run away. Still they stood, immobile, while Coulter’s men were falling by the score…
But not every officer in Christian’s brigade was willing to sit by. The 90th Pennsylvania’s Colonel Peter Lyle had personally heard Coulter’s plea for help and knew someone here had to act. “We received no orders what to do and the balance of the brigade was at a standstill in the hollow of the woods,” recalled Major Alfred Sellers, “…without waiting for any command from anyone, for certain reasons, Colonel Lyle marched the 90th out of the East Woods into a pasture or rock ledge field. Coulter’s plea was irresistible; there were no orders from higher authority.” Pulling out of the brigade’s main line, Lyle drove his men through the woods and into the grassy field beyond. The Confederate artillery fire that had ripped through the woods now focused on them alone, but on they pressed. Cresting the ridge north of the Cornfield brought Hartsuff’s thinning line into view, giving them new purpose. Identifying a hole in the line, Lyle aimed his regiment for the widening gap between Hartsuff’s 11th Pennsylvania and the 13th Massachusetts. And as they marched through this gap, they suddenly halted and opened fire. Despite their exposed position, the 90th men now stood as a wall between Hartsuff’s men and the Rebels. And with help finally arrived, Colonel Coulter returned his command to the safety of the East Woods. Fortunately for the men of the 90th Pennsylvania, they could see the Rebs falling back from their front and facing to their left to move off the field. It seemed they had come into the fight at just the right time. 
Sometime after the 90th Pennsylvania left to aid Hartsuff’s brigade, the rest of Christian’s brigade finally moved into battle. General Seymour, seeing the fresh regiments standing only yards away from his thinning, weary lines, decided that this was just what he needed. Riding up to the remainder of the brigade, Seymour directed them to march due south through the heart of the East Woods, replacing his weary Pennsylvania Reserves. Upon reaching the southern end of the woodlot and the left flank of the 90th Pennsylvania they halted to await whatever came next, orders from above or the next wave of enemy assault. Christian’s regiments would not have to wait long to see what was next in store for them because barely had they formed their line when a body of the enemy moved up on the right of Trimble’s brigade and immediately opened fire. This was Ripley’s brigade, which had been ordered by General D.H. Hill to leave its position in the sunken road position and go to the front. As Ripley’s line moved into position, the weary men of Trimble’s brigade fell back, quite willingly trading places with these fresh troops with full cartridge boxes. But as they moved Trimble’s Brigade left behind the 21st Georgia. Having been detached at the opening of the battle to deploy on the rock ledge, they failed to receive the orders to fall back. So while the rest of the brigade moved to the rear and well-deserved rest, the Georgians would have to continue holding on against Christian’s brigade as it deployed in the woods. Unlike the rest of their brigade, for better or worse, the 21st Georgia still had a critical role play in this fight. 
The retreating Confederate troops of Lawton’s and Hays’ brigades were certainly glad to retire but they weren’t fleeing and in fact were clearing the way for fresh troops of Jackson’s next attack. Into the rear of this open position swept the men of Hood’s division. Wofford Texas Brigade on the left and well to their right, Evander Law’s brigade. Barely were they in position when they started northward.
Across the Cornfield the 90th Pennsylvania boys were watching the Rebel deployment. A quick look around would have shown that the 90th was the only Union force on that part of the field in any condition to fight, so the columns of enemy troops streaming across the road and deploying for battle must have worried them greatly. Making things even worse, they could see another column of men moving across the fields from a concealed position on their left, headed toward their right; to the men of the 26th and 94th New York from Christian’s brigade these men seemed to be walking right behind the Mumma farmhouse which was now consumed in flames and bellowing smoke into the morning sky. In more ordinary circumstances the burning house and tower of smoke it was sending skyward would have been the focus of the New Yorkers’ rapt attention. But this morning, they paid more attention to the marching troops and the fact that they could see only their heads. They had no way to know it, but the New Yorkers were witnessing Colquitt’s brigade, another unit from General Daniel Harvey Hill’s division, moving into position to support Hood. For Christian’s men and the 90th Pennsylvania, the surging Confederate presence was nothing but trouble. And in but a few minutes, they would find out just how much trouble they could be. 
Colonel Law ordered his Southern regiments over the road and into the grassy field beyond. “I found but few of our troops on their field, and these seemed to be in much confusion,” recalled Law. What remained of Lawton’s and Hays’ brigades clearly couldn’t hold this field should the Yankees attack, so Evander Law moved his brigade into a battle line facing northeast to strike quickly and retake the Cornfield before the Yankees could act to stop him. Their objective was simple and straightforward: strike for the southern end of the East Woods. The presence of Union troops swarming all throughout their objective, though, suggested that reaching and taking this spot would be anything but simple and straightforward. Across the open field Laws’ men advanced, dressing their lines as best they could, given the incessant Yankee shelling they were enduring. 
Receiving word that the 4th Alabama was coming up as reinforcements, Colonel Law ordered the three regiments of his brigade already in line to move at the left oblique—which took them in a northeasterly direction—and right at the 90th Pennsylvania. Though the regiment seemed intent on holding its ground, Law knew the simple arithmetic of the moment. His three regiments—soon to be bolstered by the 4th Alabama—outnumbered the Yankees and with a determined frontal assault, could overwhelm them in front and in flank.
As the Rebs came directly at them, the men of the 90th Pennsylvania poured forth volley after volley, joined by Thompson’s and Matthews’ Batteries on their right from beyond the Cornfield. But, still, on pressed Law’s men, surging up to and around the Pennsylvanians’ flanks. “We were at this time losing men rapidly,” remembered Lieutenant George Watson of the 90th’s Company H, “and only a few minutes thus engaged, when it was observed that we being outflanked on our right, there we directed our fire.” As the 90th’s Major Alfred Sellers noted, “solitary and alone, we gave and took our medicine.” But the firing on the threatened right flank did nothing to save the left, which was at that same moment being turned, too. And the center of Law’s line was nearly on top of the Pennsylvanians. As the two lines nearly merged, the casualties grew at an alarming rate. Men were shot but unable to say by whom or even if it was from the enemy or from within their own ranks. Every company of the 90th Pennsylvania suffered casualties in this fight. But for a brief time, despite this carnage, what occupied many of the 90th’s men was a threat to the safety of their colors. 
Four paces out front of the regiment’s position—just as dictated by the drill manual, though perhaps not by common sense—stood the regimental color guard. The theory was that placing them ahead of the main line would permit the two ranks to keep their alignment while also looking generally forward, rather than to the side. This situation worked well on the parade ground but in battle it tended to make the color guard—already a choice target—a most deadly unit in which to serve. The 90th’s color guard had remained in their post in front of the regiment the whole time since their advance from the rear of the East Woods. And now, standing firm, they were closer to the enemy than anyone else in the regiment, as was the regiment’s loved national flag. Just as the flanks were being turned, a volley felled the regiment’s color bearer, Corporal Theodore Mason, who had been standing his post and cheering on his firing comrades. As Mason fell dead to the ground so went his charge, the national color. Seeing an opportunity, several Rebs swarmed forward from Law’s center and grabbed the flag. Wrenching it from Mason’s death grip, they tripped over each other to get their prize safely to the rear. But at that same moment, ten or so men from the center of the 90th bolted from their ranks to reclaim their flag. As they two groups met, a small, very personal battle broke out within the larger fight in the Cornfield.
Desperate, hand-to-hand fighting erupted between the two opposing groups, both equally bent on securing their own form of victory. Private William H. Paul of the 90th Pennsylvania’s Company E recalled, “We clashed with a shock, and a sharp hand-to-hand fight ensued in which two of our men were killed and five so severely wounded that they were unable to be of further assistance.” But Paul was committed to the task, not thinking about his actions so much as doing whatever was needed to get that flag. His very being at that moment was dedicated to rescuing the colors. “A Rebel had already seized the colors but I grasped them and with one supreme effort wrenched the precious banner from his hold.” Though he didn’t record what happened next, Private Paul almost certainly raced for the rear of the regiment’s position and safety rather than risk losing it again. It was an act of heroism borne of bravery or unthinking rashness. But regardless, it was an act that earned William Paul the Medal of Honor. 
Whether it was the return of their colors or the fact that they were nearly surrounded, the 90th Pennsylvania immediately withdrew, following their new color bearer toward the safety of the East Woods. Colonel Lyle, who’d remained at his post with the regiment despite being severely wounded in the side, ordered a retreat and had no trouble at all getting the men to comply. Veterans of the 90th would later claim that their retreat had been orderly; “the color bearer walking backward, the men turning and firing until it entered the woods, when it hurriedly pushed through them…” Nonetheless, there was confusion amidst this order. Private John Howell from Company B recalled that “the line was in retreat or falling back. I was in between the two fires. Some of us heard the order to retreat and some of us did not.” The confusion about what he should be doing would earn the private a nearly fatal wound in the back of his head. But John Howell was hardly alone. When the final toll was counted it would show the regiment had lost nearly half of its 200 man roster. Another man who remained behind was Lieutenant Hillary Beyer, who voluntarily remained to care for the wounded and carry them to safety, ultimately earning the 90th Pennsylvania’s second Medal of Honor that day.
As the 90th Pennsylvania slipped hurriedly into the woods, they opened the east end of the Cornfield to Confederate control once again. The only other Union hold on this part of the field—the southern end of the East Woods, key to Hooker’s attack and the security of the Union’s advanced left flank—consisted of the rest of Christian’s former brigade. But without strong, clear leadership or purpose Christian’s men were quickly driven out by Evander Law’s advancing troops. Law’s Texans, Georgians, and Alabamians poured into the East Woods driving away Christian’s Pennsylvanians and New Yorkers, removing the Union threat to the Confederate right flank and securing Confederate control over the southern end of the East Woods. It was a development that was to bedevil Union efforts to strike the Confederate position at the Dunker Church and play a key role in turning Antietam into a costly stalemate. 
For his leadership at Antietam, Colonel Lyle was promoted to command the brigade in Christian’s place, while Lieutenant Colonel Leech assumed command of the 90th. After participating in the Battle of Chancellorsville, the 90th Pennsylvania returned home as the regiment marched toward Gettysburg. There on July 1st, the 90th took part in the defense of McPherson’s Ridge on that battle’s first day. They fell back though town late in the day along with the rest of the I Corps toward a spot on the southern end of Cometary Ridge. En route there, the 90th’s chaplain, Horatio Stockton Howell, was cruelly murdered by Confederate troops on the steps of the town’s Lutheran Church.
In 1864 the 90th was reassigned to the V Corps’ Second division, First brigade ahead of its participation in the Overland Campaign. In addition to enduring the horrors of Cold Harbor and nearly a dozen of the campaign’s other actions, the Battle of the Wilderness cost the 90th Pennsylvania significant casualties—124 of its 251 men present—while at Spotsylvania the regiment lost nearly 100 men. 
The regiment participated in the siege of Petersburg, although the action at Globe Tavern (or the Second Battle of the Weldon Railroad) most sorely tested the men. During that battle, from August 18th – 21st, the regiment saw Colonel Leech and 90 other officers and men captured when Confederates overran its position (in addition to losing 20 others killed and wounded). 
The 90th Pennsylvania was disbanded on November 26th, 1864 when its term of service expired. Most of the survivors were shipped home to Philadelphia to be discharged, while those with time remaining on their enlistment were transferred to the 11th Pennsylvania Infantry for the remainder of the war.
All told, the regiment lost 230 men to death during its service. At the same time, the 90th Pennsylvania could boast of seven Medals of Honor in its ranks, two of which had been earned within the horrors of Antietam’s bloody Cornfield.
 James Durkin, The Last Man and the Last Life: The Bloody Journey of the Philadelphia National Guards Regiment from May 1861 to November 1864 (Glenside, PA: J.M. Santarelli, 2000), pp. 3-9.
 Durkin, The Last Man and the Last Life, pp. 13-15.
 Durkin, The Last Man and the Last Life, pp. 51-59.
 Durkin, The Last Man and the Last Life, pp. 78-82.
 National Archives, Record Group 94, Antietam Battlefield Studies, 31 December 1894 letter from Alfred Seller to Gould, p. 2; 5 January 1895 letter from Alfred Sellers to E. A. Carman,. 2; Durkin, The Last Man and the Last Life, p. 87.
 Ezra A. Carman and Joseph Pierro, Ed. The Maryland Campaign of 1862; Ezra A. Carman’s Definitive Study of the Union and Confederates at Antietam. (New York: Routledge Books, 2008), p. 224
 Carman, The Maryland Campaign, pp. 224-225.
 Thompson’s Union battery was almost certainly what was giving Law’s men such trouble—not, as some Confederates would later claim, Campbell’s guns which remained busy with Wofford’s attacking brigade.
 W. F. Beyer and O. F. Keydel, Eds. Deeds of Valor (Platinum Press, Detroit, 1903), p. 90.
 Beyer and Keydel, eds. Deeds of Valor, p. 90.
 Carman, The Maryland Campaign, pp. 227-228.; OR, Vol. XIX, Pt. 1, pp. 937-938.
 Durkin, The Last Man and the Last Life, pp. 221-226.
 Durkin, The Last Man and the Last Life, pp. 272-276.