On the 6th of November, 1861, Robert E. Patterson, of Philadelphia, having received authority to raise a regiment, selected officers and commenced recruiting. On the 28th of January, 1862, Captain John P. Dunne, of company B, was ordered to proceed with all the men then enlisted, to Hestonville, and establish there a camp of rendezvous and instruction. After remaining a little more than a month, the command was ordered to Camden, New Jersey, and went into camp near Diamond Cottage. The field officers were as follows:

• Robert E. Patterson, Colonel
• Robert Thompson, Lieutenant Colonel
• Frank A. Lancaster, Major

The men were principally from Philadelphia, with the exception of companies D and G, which were recruited in the counties of Cambria, Lebanon, and Lancaster. While in camp, the officers were regularly instructed, and the men properly drilled.

On the 31st of May, the regiment broke camp and proceeded by rail to Harrisburg, where it was employed in guarding a body of about five hundred rebel prisoners. On the 25th of June, the regiment was ordered to the Peninsula to join the army of General M'Clellan, now in close proximity to the city of Richmond, and about to commence his celebrated change of base.

Lieutenant Colonel Thompson, with company C as an escort, took the prisoners which the regiment had been guarding, to Fort Delaware, re-joining the command at Baltimore. On the 28th it arrived at Fortress Monroe, and settled at Camp Hamilton, where it awaited the direction of the commanding general.

On the 4th of July it was ordered to Harrison's Landing, where the entire army was assembling. Company B, under command of Captain Dunne, was left to bring up the camp equipage and quartermaster's stores, which were embarked on the steamer Juniata. When this vessel had arrived within about seven miles of the Landing, the enemy opened on her from a light battery posted on a commanding bluff, threatening her entire destruction, as she had run aground and could not be got off without lighting, or awaiting the rise of the tide. A gunboat, lying just below, came up to her assistance, and with its ponderous shells soon drove the enemy away. The Juniata was finally got afloat by throwing overboard the equipage and stores, and proceeded on its way without further molestation, having been struck by the enemy's fire eleven times.

Upon its arrival, the regiment was assigned to General Francis E. Patterson's Brigade,¹of New Jersey troops. On the 4th of August, Hooker's Division was ordered back to Malvern Hill, where a body of the enemy was met and driven. In this affair, the regiment was commanded by Lieutenant Colonel Thompson, Colonel Patterson being in temporary command of the brigade. On the 15th, the regiment marched to Yorktown, and on the 23d embarked for Alexandria, where, upon its arrival, two days later, it encamped on the outskirts of the town, the entire army being now on its way from the Peninsula, to join General Pope, in command of the Army of Northern Virginia.

On the 26th, the division moved by rail to Warrenton Junction, and on the following morning marched to Bristoe Station, where the enemy under Jackson had suddenly made his appearance, far in the rear of Pope's Army. The regiment, in command of Lieutenant Colonel Thompson, Colonel Patterson, from sickness, being unable to lead, was brought into position on the left of the Fifth New Jersey, under a heavy fire of shot and shell. For two hours the position was held with great gallantry, when a charge was ordered, before which the enemy could no longer stand, but retreated rapidly towards Bull Run. Major Lancaster was severely wounded in the left arm, and Lieutenant R. L. Thompson in the neck. A number of the men were killed and wounded.

The regiment bivouacked upon the field at night, and early on the following morning, started in pursuit, arriving at Centreville in the afternoon, and continuing on towards Bull Run. At the opening of the battle on the morning of the 29th, the regiment was brought up to the front, by Lieutenant Colonel Thompson, and placed in position on the left of the Seventh New Jersey, where for five hours it held its ground, making two charges across an unfinished railroad cut, near the line of battle. The regiment was relieved at the front by the Second Maryland, at five in the afternoon, and retired to the second line. The loss in this day's fighting was five officers and thirty-four men in killed, wounded, and missing.

On the morning of the 30th, along with the brigade, the regiment moved in pursuit of the enemy, who was supposed to be retreating. On reaching the Sudley Spring Road, he was, however, found in force, and the brigade was immediately formed to support batteries, where it was exposed to a hot fire of shot and shell. Towards the close of the day, the brigade was ordered to the left, and while passing across the field, came under a torrent of deadly missiles hurled from the enemy's artillery. At sunset Hooker's Division moved from the field, and at midnight bivouacked near Centreville. On the following day it marched to Chantilly, where, in the fierce battle which was fought near the close of the day, Hooker supported the division of Kearny.

After this disastrous campaign, the regiment was ordered into the defences of Washington, where it remained until after the return of the army from Maryland. Early in November it re-joined the army, and was encamped at Catlett's and Bristoe Stations, and at Manassas Junction. On the 8th of November, Colonel Patterson was ordered to Philadelphia, to have charge of drafted men, and in the absence of the Lieutenant Colonel and Major, the former on account of physical disability, having lost his hearing, the latter from wounds received at Bristoe Station, Lieutenant Colonel Olmstead, of the Second New York, was placed in command of the regiment. On the 16th the brigade was ordered to join the army near Falmouth, and upon arriving at Wolf Run Shoals, went into camp. Here the commander of the brigade, General Francis E. Patterson, died.

On the morning of 13th of December, the battle of Fredericksburg opened, and the brigade, now in the centre grand division, under Hooker, crossed the river on Franklin's pontoons, below the town. Moving to the front, it formed line of battle on the Fredericksburg Road, the regiment on the extreme left of the brigade, connecting on its right with the Eighth New Jersey. As the line advanced across the plain, south of the road, it came under a terrific enfilading fire of shot and shell, from which it was forced to fall back to the road. Reforming, it again advanced and maintained its position. At midnight of the 15th it commenced falling back, it having been decided to abandon the contest, and with the army re-crossed the river, encamping near Falmouth.

In Burnside's second campaign, which had to be abandoned on account of impassable ways, the regiment was employed in building corduroy roads, and in severe fatigue duty, in moving the artillery and trains. On the 15th of January, 1863, Adjutant William C. Ward was promoted to Lieutenant Colonel, and Captain John P. Dunne to Major, the former releving Colonel Olmstead. Lieutenant Colonel Lancaster had been promoted to Colonel, upon the resignation of Colonel Patterson, but was still incapable of returning to duty on account of his wounds.

On the 3d of February, in pursuance of orders, the division moved out to Rappahannock Station and destroyed the bridge near by, the regiment sustaining no loss, and returning to camp when the destruction was complete. In April Colonel Lancaster re-joined the regiment, and Lieutenant Colonel Ward resigned.

Upon the opening of the Chancellorsville campaign, the Third Corps, now under command of General Sickles, was at first moved to the river below Fredericksburg, to cover the crossing of the Sixth Corps, but afterwards joined the main body of the army. The regiment left camp on the 28th of April, and marched to the crossing of the Rappahannock below Fredericksburg, where it remained until the morning of the 30th. It then marched to the United States Ford, and bivouacked for the night, picketing the river in its front.

Crossing the river it moved out to the front, and with the brigade took position on the left of the plank road, and in rear of the First Division. At daylight on the morning of the 3d, the first line was attacked, and after maintaining its position for an hour, was driven back upon its supports. The second line was then ordered to advance. With alacrity it sprang forward, driving the enemy, when Colonel Lancaster fell, pierced through the temple by a minie ball, the command devolving on Major Dunne.

Without faltering, the line pressed forward, re-capturing the breast-works, and taking four hundred prisoners and two stands of colors. Not satisfied with this success, it crossed the works and pushed the enemy back through the woods in front. Here he was strongly reinforced, and returning to the charge, drove the brigade back about four hundred yards, where it rallied to the support of Dimick's Battery, of the First Regulars. Emboldened by his temporary success, he came on, to within two hundred yards of Dimick's guns, when the brigade, though fearfully decimated, charged and drove him back into the woods again. Again he advanced, and again he was driven before the steady fire and cool courage of the men of this brigade. The position was held against the desperate efforts made to carry it, and the guns faithfully protected until relieved, when it retired a short distance to the rear. The regiment had not rested long before it was again ordered to the front, where a new line of battle having been formed, and where until the close of the engagement, on the night of the 6th, it was exposed to an almost constant fire. With the army it fell back, and re-crossing the river, returned to its former camp near Falmouth.

The regiment entered the battle with fourteen officers and two hundred and thirty men; of these, Colonel Lancaster, and Captains John J. Connelly and George Cromley, were killed, and Captains Richard Dillon and Wm. A. Reilly, and Lieutenants William J. Ashe, James Malloy and Evan Davis, were wounded, the two latter mortally. Captain Dillon lost his left arm. Eight men were killed, seventy-three wounded, and twenty-two missing; an aggregate loss of one hundred and eleven.

The monotony of camp life was little varied until the opening of the Gettysburg campaign, about the middle of June. On the 29.th, it was at Taneytown, where it was engaged in provost duty, and at Emmettsburg on the following day, again in the same duty. The corps arrived on the battle-field on the evening of the 1st of July, after the fighting of the first day was over.

The.regiment, in command of Major Dunne, joined its brigade on the morning of the 2d, and was posted at ten A. M., near, and in front of Round Top; but the position being considerably in advance of the line of battle, was untenable. The enemy, seeing its exposure, poured in his shells in a merciless torrent, and forced it to fall back to the main line. The regiment was then posted along a wooded eminence to the south-east of the wheat-field, under cover of a low stone wall, the Eighth New Jersey joining it on the right.

At 3 P. M., the enemy advanced to the attack, and succeeded in breaking through the lines, to the right and left of the ground where the regiment stood. Still it held its position, preserving its ranks intact. Finally the enemy poured through the breach which he had made, upon other parts of the line, and came upon its flank, compelling it to fall back. It retired in good order to a point where a Union battery was hotly engaged, and in imminent danger of being lost. Halting and quickly forming, it checked the mad onset of the enemy until the guns could be limbered and taken away, when it was ordered to kneel in the tall wheat and again open fire. Thus the foe was held at bay, until relieved by Caldwell's Brigade, of the Second Corps. But before retiring, it was again called on to charge, which was gallantly executed, driving the rebels, now swarming out on all sides, back into the woods. It was then withdrawn, and re-joined the brigade at the rear.

On the morning of the 3d, it was early brought to the front, and formed in battle-line. At three o'clock in the afternoon, it was hurried away at double-quick to the support of the Irish Brigade upon the left centre, but did not reach the threatened point in time to render any assistance. On the following day the enemy retreated, and the Union army joined in pursuit. The loss in this battle was severe.

After re-crossing the Potomac, the two armies moved on south, and at Wapping Heights, near Front Royal, the Third Corps encountered a body of the enemy, which was driven, after a slight skirmish. Moving forward, the regiment reached Warrenton on the 26th, and Bealton Station on the 30th, where it went into camp. A month later, it advanced to Culpepper, where it again encamped. On the 10th of September, Major Dunne was commissioned Lieutenant Colonel, and Captain William A. Reilly, Major.

In October, General Page Meade, finding that the enemy was endeavoring to turn his right flank, retreated rapidly to Centreville. On the 15th, the regiment was sent forward to Blaine's Ford, on Bull Run Creek, to the support of the Sixth New Jersey, which was across and entrenehed on its, right bank, and took position behind an old breast-work on the left bank. The enemy attacked the Sixth in its entrenchments, and drove them out, making strenuous efforts to cut it off from retreat to the ford. Unperceived by the enemy, the One Hundred and Fifteenth awaited until he had come within easy musket range, when it sent a volley into his ranks, throwing his forces into confusion, killing and wounding several, and driving the rest back into the woods until the Sixth had retired and safely crossed. A steady fire was kept up by the regiment until it was relieved. It lost several wounded.

In the advance, which followed hard upon the retrograde, the corps, under Birney, met the enemy near Kelly's Ford, where a brisk skirmish ensued. On the 26th of November, while following up the retreating enemy, the brigade was ordered to Mitchell's Ford to hold it, lest the enemy should make a dash upon the flank of the army.

On the 27th, having re-joined the division, now under General French, it crossed the Rapidan at Culpepper Mine Ford. During the afternoon, the regiment was engaged in skirmishing through the wood that skirts Mine Run, for the purpose of finding the right of the enemy's works. At midnight it marched and took up position in line of battle in Warren's lines, in readiness for the intended assault on the enemy entrenched behind Mine Run, on the following morning. The assault was not made, and the campaign was abandoned. Returning, the regiment went into winterquarters at Brandy Station.

With ten officers and one hundred and forty men, the regiment broke camp on the 3d of May, 1864, and with the brigade commanded by General Mott, now forming part of Birney's Division, of Hancock's Corps, marched for the Wilderness. On the 5th it met the enemy, having three men wounded; on the 6th, having one man killed, and two officers and eight men wounded; and on the 7th, two men missing.

Moving on to Spottsylvania, the enemy was again found in strong works, and fighting re-commenced more stubborn and sanguinary than ever. In the charge of the corps on the morning of the 12th, the regiment lost six wounded; in the fighting of the following day, one killed, four wounded, and one missing; and in the struggle which was kept up until the 20th, it met some loss almost daily.

Again taking up the march, it passed Bowling Green and Milford, and on the 23d reached the North Anna River. Shortly after daylight on the following morning, the enemy being observed in his works on the opposite side of the stream, the brigade was ordered across to attack. The wooden bridge over which it passed was raked by the enemy's artillery, which was kept in full play; but it succeeded in gaining the opposite bank, when the enemy retreated rapidly, and the division occupied his intrenchments. Re-crossing the river on the 26th, it moved on until again stopped at Tolopotomy Creek, on the south bank of which the enemy was strongly intrenched. His advanced lines were carried, but his main works proving too strong to be overcome by direct assault, the army again moved by the left to Cold Harbor.

At dawn of the 3d of June, Gibbons' and Barlow's divisions assaulted the enemy's works here, supported by Birney's, of which the One Hundred and Fifteenth formed a part, and carried them, capturing several hundred prisoners, one color, and three guns. Being reinforced, the enemy in turn assaulted, and compelled the corps to withdraw about seventy-five yards, where it intrenched.

On the 15th, the regiment crossed the James, and with the corps moved up in front of Petersburg. It was immediately ordered out on the skirmish line, and at four in the afternoon of the 16th, simultaneously with the enemy, the corps advanced, when a fight opened which lasted until after dark, the enemy being driven back along the whole line. He made several attempts during the night to re-gain his lost ground, but all to no purpose. The regiment lost one officer, Captain Robert M. Jeffries, killed, three men wounded, and one missing.

On the 18th, the enemy having retired from his first line of works, the division again advanced to the attack, in two lines of battle, but was repulsed, the regiment losing four wounded. On the 21st the corps moved to the left, to the Jerusalem Plank Road, taking position on the west side, and connecting with Griffin7s Division of the Fifth Corps. On the following morning it advanced, and commenced throwing up breast-works; but before they were completed, the enemy attacked Barlow's Division on the left, and drove it back, thus exposing the left of the Third Division of the Second Corps, to which the regiment belonged, compelling it to fall back to the position of the previous evening. The loss was one man killed.

The regiment had now become greatly reduced, having but seven officers and eighty-four men present for duty. Accordingly, by special order of the War Department, it was consolidated into three companies, and incorporated with the One Hundred and Tenth Regiment, with which it served until the close of the war, and was mustered out of service with that organization on the 28th of June, 1865. The company officers were retained in service, but the field and staff were mustered out on the 23d of June, 1864.

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¹Organization of Third Brigade, Hooker's Division, Third Corps. Fifth Regiment New Jersey Volunteers, Colonel Samuel E. Starr; Sixth Regiment New Jersey Volunteers, Colonel Gersham Mott; Seventh Regiment New Jersey Volunteers, Colonel Joseph W. Revere; Eighth Regiment New Jersey Volunteers, Colonel Adolphus J. Johnson; One Hundred and Fifteenth Regiment Pennsylvania Volunteers, Colonel Robert E. Patterson.

Source:  Bates, Samuel P. History of the Pennsylvania Volunteers, 1861-65, Harrisburg, 1868-1871.

Organization:

Organized at Philadelphia and Harrisburg January 28, 1862.
Moved from Camden to Harrisburg, Pa., May 31, 1862, thence to Camp Hamilton, Va., June 25-28, and to Harrison's Landing, Va., July 4.
Attached to 3rd Brigade, 2nd Division, 3rd Army Corps, Army of the Potomac, to March, 1864.
1st Brigade, 4th Division, 2nd Army Corps, to May, 1864.
3rd Brigade, 3rd Division, 2nd Army Corps, to June, 1864.

Service:

Duty at Harrison's Landing, Va., till August 16, 1862.
Movement to Centreville August 16-26.
Action at Bristoe Station or Kettle Run August 27.
Battles of Groveton August 29; Bull Run August 30.
Duty in the Defences of Washington till November.
At Fairfax Station November 2-25.
Operations on Orange & Alexandria Railroad November 10-12.
Duty near Falmouth, Va., November 28-December 11.
Battle of Fredericksburg December 12-15.
Burnside's 2nd Campaign, "Mud March," January 20-24, 1863.
Operations at Rappahannock Bridge and Grove Church February 5-7.
Chancellorsville Campaign April 27-May 6.
Battle of Chancellorsville May 1-5.
Gettysburg (Pa.) Campaign June 11-July 24.
Battle of Gettysburg July 1-3.
Pursuit of Lee July 5-24.
Wapping Heights,Va., July 23.
Duty near Warrenton, Va., till October.
Bristoe Campaign October 9-22.
McLean's Ford, Bull Run, October 15.
Advance to line of the Rappahannock November 7-8.
Kelly's Ford November 7.
Mine Run Campaign November 26-December 2.
Payne's Farm November 27.
Demonstration on the Rapidan February 6-7, 1864.
Duty near Brandy Station till May.
Rapidan Campaign May 4-June 12.
Battles of the Wilderness May 5-7; Spottsylvania May 8-12; Spottsylvania Court House May 12-21.
Assault on the Salient May 12.
North Anna River May 23-26.
On line of the Pamunkey May 26-28.
Totopotomoy May 28-31.
Cold Harbor June 1-12.
Before Petersburg June 16-18.
Consolidated with 110th Pennsylvania Infantry June 22, 1864.

Losses:

Regiment lost during service

6 Officers and 32 Enlisted men killed and mortally wounded and
2 Officers and 40 Enlisted men by disease. Total 80.

Source:  Dyer, Frederick H. A Compendium of the War of the Rebellion Compiled and Arranged from Official Records of the Federal and Confederate Armies, Reports of he Adjutant Generals of the Several States, the Army Registers, and Other Reliable Documents and Sources.Des Moines, Iowa: The Dyer Publishing Company, 1908