One of two military units raised at roughly the same time in the Philadelphia area during the fall of 1862, the 157th Pennsylvania was stationed initially at Fort Delaware, beginning in December 1862, and remained there on garrison duty until it was reassigned to the defense of Washington, D.C. during the early winter of 1863.

[1][2] Raised in response to the continuing need for additional soldiers to support the Union Army during the American Civil War, the 156th and 157th Pennsylvania Volunteer Infantry regiments began their respective recruiting drives in the Philadelphia area during the fall of 1862.

[3][4] The men of the newly reorganized 157th Pennsylvania were then transported to Washington, D.C., attached to Tyler's Division, 22nd Corps in February 1863, and assigned to defensive duties of the city.

He then enrolled with the 157th Pennsylvania on October 16, 1862, was commissioned as a first lieutenant and regimental quartermaster with the battalion's field and staff officers' corps on December 16, and was then honorably discharged on February 27, 1863.

[14][15] John Wallace Scott was wounded in action multiple times while serving with the 157th Pennsylvania, and was then awarded the U.S. Medal of Honor for his gallantry during the Battle of Five Forks, Virginia on April 1, 1865.