The monument to the 102nd Pennsylvani is south of Gettysburg near Wheatfield Road. (39.79745° N, 77.2374° W; Google map; Tour map: Crawford Ave. & J. Weickert Farm) It was dedicated in 1889 by the Commonwealth of Pennsylvania.

Monument to the 102nd Pennsylvania Infantry at Gettysburg

While most of the regiment guarded trains and picketed roads in the rear, a detachment of 103 men commanded by Lieutenant Robert W. Lyon arrived at Gettysburg with a supply train and was thrown into the defensive line north of Little Round Top. They suffered no casualties.

6th Corps Headquarters Flag 6C-3D

From the front of the monument:

102nd Pennsylvania Infantry

3rd Brigade, 3rd Division, 6th Corps

From the left side:

July 1. The Regiment was detailed at Manchester to guard trains to Westminster. At the latter place a detachment of 3 officers and 100 men was sent to Gettysburg with the supply train and on its arrival the morning of the 3rd was posted on this line. The rest of the Regiment picketed the roads leading from Westminster to Gettysburg until the close of the battle.

From the right side:

Recruited in Allegheny and Butler Counties
Mustered in August 1861. Re-enlisted December 1863
Mustered out June 28, 1865.
Total enrollment 2100.
Killed and died of wounds 10 officers 169 men
Wounded 23 officers 518 men
Died of disease, etc.1 officer, 37 men
Captured or missing 5 officers 131 men
Total 39 officers 905 men

From the rear:

Yorktown, Williamsburg, Fair Oaks, Malvern Hill, Antietam Fredericksburg, Marye’s Heights, Salem Heights, Gettysburg, Rappahannock, Mine Run, Wilderness, Spotsylvania, North Anna, Totopotomoy, Cold Harbor, Petersburg, Fort Stevens, Charlestown, Opequon, Fisher’s Hill, Cedar Creek, Petersburg Fort Fisher, Petersburg Assault, Sailor’s Creek, Appomattox

See more on the 102nd Pennsylvania Volunteer Infantry Regiment in the Civil War