[1] The regiment was recruited in Allegheny, Berks, Dauphin, Luzerne, Mifflin, Northampton, Northumberland, and Potter counties, and mustered into service on September 4, 1861, under the command of Colonel Joseph F. Knipe.

[2] From late September 1861 through February 1862, the 46th was stationed on the upper Potomac River in Maryland, performing guard and outpost duty in Brig.

After a brief foray to Manassas, they were ordered back to Winchester and subsequently started a long march up the Shenandoah Valley, reaching as far south as Harrisonburg.

However, with no Union reinforcements immediately sent to sustain this breakthrough, and with pressure from additional Rebel troops sent to shore up and rally this end of the line, Crawford's men were soon outflanked and forced to retreat back across the wheat field.

[9] Subsequent to having taken part in Maj. Gen. Ambrose Burnside's Mud March January 20–24, 1863, the 46th went into winter camp at Stafford Courthhouse, Virginia and remained there into late April.

Thus organized, at the end of April, the regiment marched up the Rappahannock River around Gen. Robert E. Lee's left flank, on their way toward the Battle of Chancellorsville.

[10] Generally, the XII Corps played a significant role throughout the battle in defending their part of Hooker's line and covering the army's retreat afterward.

[12] In September, the XI and XII Corps were detached from the Army of the Potomac and transferred west by rail to Tennessee to aid Maj. Gen. William Rosecrans, who was besieged in Chattanooga.

In this battle, the men had stacked their arms toward the rear of a position they had just begun to fortify with breastworks, when suddenly two divisions of Confederate troops appeared in the clearing.

After running to retrieve their rifles and loading them as they returned to the line, the 46th and the rest of their brigade, supported by artillery, proceeded to handily repulse the Rebels, inflicting terrible casualties, but incurring very few of their own.

[15] In mid-July, with Sherman practically on the doorstep of Atlanta, Confederate President Jefferson Davis demonstrated his dissatisfaction with Gen. Joseph E. Johnston's efforts to stop him by relieving him of command and placing the troops under Gen. John Bell Hood instead.

Living up to his aggressive and often reckless nature, Hood wasted little time in ordering an attack on the Union forces near Peachtree Creek.

Late in the afternoon on July 20, the Confederates assaulted Union Maj. Gen. George Henry Thomas' Army of the Cumberland, to which the XX Corps was assigned, catching them completely off guard.

After occupying Atlanta for two and a half months, the Union forces then set out on Sherman's March to the Sea, with the 46th among the ranks, on November 15, ending with the capture of Savannah, Georgia, on December 22.