125th Pennsylvania Infantry Regiment

In his memoirs General William T. Sherman decried a systematic problem which the 125th Pennsylvania fell prey to at Antietam, along with many other Regiments in their initial battles:

The greatest mistake in our civil war was in the mode of recruitment and promotion. When a regiment became reduced by the necessary wear and tear of service, instead of being filled up at the bottom, and the vacancies among the officers filled from the best non-commissioned officers and men, the habit was to raise new regiments, with new colonels, captains, and men, leaving the old and experienced battalions to dwindle away into mere skeleton organizations.[24]

Significantly, Antietam was the last battle fought in the east without the construction of field fortifications, although naturally occurring features, such as the Sunken Road and the quarry holes above the Burnside Bridge, were exploited as rifle pits. Three months after Antietam at Fredericksburg, several of Longstreet's divisions fought behind breastworks, and eight months after Antietam at Chancellorsville, both armies constructed hasty fortifications at every opportunity.[25]

125th Pennsylvania Infantry Monument at Antietam National Battlefield

Color Bearer, Sergeant George A. Simpson: #3953 at Antietam National Cemetery

The 125th Pennsylvania Volunteer Infantry Monument on the Antietam Battlefield was dedicated on September 17, 1904, and is located on Confederate Avenue behind (West) of the Dunker Church.[27] During the 125th Pennsylvania's withdrawal from the indicated position in the West Woods, one of the most dramatic events in the regiment's history began with the regimental color-bearer, Sergeant George Simpson who stands immortalized in granite on top of the monument:

After receiving a bullet to the brain, Simpson fell on the flag and stained it with blood oozing from his right temple. Corporal Eugene Boblitz of Company H grabbed the colors and was soon felled with a leg wound that crippled him for life. Several other soldiers were shot trying to save the colors. Finally, Sergeant W.W. Greenland snatched up the bloodstained banner and passed it on to Captain William Wallace, who used it to rally the regiment. About 200 men formed in line, and about 60 gathered around the much-contested colors in protection. In the twenty-first century, there is often much debate over how we treat the flag. In the Civil War, there was none. Many soldiers were willing to give their lives for that flag.[28]

XII Corps trenches are visible in the modern day. They run parallel to Slocum Drive on its southern side within 20'-60' of the modern road.

On April 27–28, the initial three corps of the Army of the Potomac began their march under the leadership of General Henry W. Slocum. They crossed the Rappahannock and Rapidan rivers as planned and began to concentrate on April 30 around the hamlet of Chancellorsville, which was little more than a single large, brick mansion at the junction of the Orange Turnpike and Orange Plank Road.

Upon reaching Chancellorsville on April 30, 1863, General Joseph Hooker deployed the Army of the Potomac in a defensive perimeter around the intersection. Slocum's Twelfth Corps held the center of the Union line, and for three days, his troops entrenched, creating a sturdy earthwork screened by a line of fallen trees known as abatis.

Movements of XII Corps, 2nd Division, on May 1 are indicated by yellow arrows. Map by Hal Jespersen, www.posix.com/CW

While Hooker still maintained the initiative, he commanded a three-pronged eastward thrust. The 1st & 3rd Divisions of the V Corps (Meade) advanced along River Road, the 2nd Division (Sykes) advanced along the Turnpike, and the entirety of the XII Corps (Slocum) advanced along the Plank Road. One mile out, Slocum (XII Corps, including the 125th Pennsylvania) encountered a Confederate picket post and reacted cautiously by deploying his two divisions in line of battle, one Division on each side of Plank Road. Advancing slowly for the next half mile in this formation, the XII Corps had just emerged onto high ground at the Alrich farm, favorable for an offensive, when a Hooker emissary, Colonel Joseph Dicksinson, reported the advance far short of objective and already engaging the enemy at about 1:30 p.m.

Simultaneously, Hooker received unfavorable reports about the progress of Sykes (V-2)(east of Chancellorsville on the Turnpike) and Sedgwick (VI)(east of Fredericksburg). Meade's (V) 1st & 3rd Divisions were advancing unimpeded toward a strategic imperative, occupation of Bank's Ford on the Rappahannock River; nonetheless, Hooker called a halt to all operations and ordered a retreat into defensive positions around Chancellorsville. Thereby, the initiative had been lost for the remainder of the battle.[31]

Between noon and 2 p.m., an armed, westward-moving force became visible and audible to the 125th Pennsylvania's 2nd Division. Private Hicks noted, "From this force we could hear an occasional command, 'Close up,' 'Steady, men,' and like words, and now and then we could catch glimpses of the gray-clothed ranks moving with steady steps, with arms at right shoulder and paying no attention either to us or to our skirmish line in front".[32] The degree of subterfuge associated with the movement was noted by Captain Wallace:

During a suspicious lull in operations, a field officer near me, training his glass on a distant woods, drew my attention to a column of the enemy moving eastward in front of that woods. It was apparently a large force, but as we kept watching it, we were surprised by the occasional reappearance of an officer on a white horse. In each instance he would emerge from our right and disappear on our left, and as it was the same officer, we found that we were witnessing a bit of war strategy, and that a small force was circling many times around that woods to convey the impression that it was an army change of base in one direction, while in reality it was moving the other way.[33]

Following the failure of the Union command to recognize and respond to General Thomas J. Jackson's flanking movement and the subsequent attack, the entire XII Corps attempted to rally the panic-stricken fugitives of the XI Corps, but they would not stop until they were either captured or reached the Rappahannock River. Ultimately, intense night-fighting, especially artillery from Hazel Grove, stemmed the attack, but the 125th Pennsylvania, along with the most of their 2nd Division, was not involved.

The 125th Pennsylvania fights along the XII Corps, 2nd Division, trench line on May 3, 1863

For two days of battle the Confederates did not test Slocum's position, but starting at 5:30 a.m. on May 3, Lee ordered a broad assault. While Virginians led by General William Mahone attacked the 2nd Division of the XII Corps, Confederate artillery on the Orange Plank Road and at Hazel Grove sent shells screeching into Slocum's line from the rear. The XII Corps gamely held its ground, but as the hours passed, its supply of ammunition ran low. At 9 a.m., Slocum ordered a retreat, and by 10a.m., fighting had essentially ceased with the Confederates in possession of Chancellorsville.[34]

Constructing effective breastworks near the Chancellor Mansion and Tavern, the 125th Pennsylvania's Regimental losses were limited (5 killed, 12 wounded, and 10 captured). On May 2, Stonewall Jackson's famous 'Flanking Maneuver' avoided the trap of breastworks placed by the III, XI and XII Corps and led to an attack on the XI Corps' rear.[35]

The fiercest fighting of the Chancellorsville Campaign occurred on May 3, including action at Salem Church and Fredericksburg, and produced the second bloodiest day of the Civil War. The smaller Confederate Army (60,892 CS men vs. 133,868 US men) experienced a significantly higher rate of casualties (22% CS vs. 13% US) than the enemy during General Robert E. Lee's 'Perfect Battle'.