The 116th Pennsylvania Infantry served as a member of Kelly’s “Irish” Brigade in Caldwell’s Division of the Second Corps, Army of the Potomac during the battle of Gettysburg, A Fighting 300 Regiment. The volunteer regiment was commanded by Maj. St. Clair A. Mulholland (1839-1910). Mulholland was a colonel in the Union Army in the American Civil War who later received the brevets of brigadier general of volunteers and major general of volunteers and the Medal of Honor for gallantry in action at the Battle of Chancellorsville. Under Mulholland's command, the regiment brought 123 men to the field, and among them, 2 were killed, 11 were wounded and 9 went missing.
Returning to civil life after the war, he was appointed Chief of Police in Philadelphia in 1868, and signalized his administration by the good order in which he kept both the force and the city. President Grover Cleveland appointed him United States Pension Agent, in which office he was continued by Presidents McKinley and Roosevelt. He was considered an authority on the science of penology, and also devoted much of his leisure time to art studies, and as a lecturer and writer on the Civil War and its records. He compiled a history of the 116th Regiment, and another of those to whom Congress voted the Medal of Honor. In the Catholic affairs of Philadelphia, he was always active and a leader among the best known laymen. St. Clair Augustin Mulholland died February 17, 1910 at Philadelphia, Pennsylvania and was buried at Old Cathedral Cemetery, Philadelphia.
The 116th Pennsylvania Infantry Monument is located on Sickles Avenue, on the right or east side when traveling north and situated at the very obvious loop on Stony Hill. The monument is off road so you have to walk a few dozen feet to get to it as it is at the woodline. The monument does not face the road, but instead, faces west. 
Parking is available at small, cutout shoulders along the road, some wide, some narrow. Be sure to stay off the grass or you will be ticketed by park police. I visited this monument on Thursday, July 5, 2012 at 2:39 P.M. I was at an elevation of 588 feet, ASL. I used a Canon PowerShot 14.1 Megapixel, SX210 IS digital camera for the photos.
The Draw the Sword site helped out by the NPS narrative, the SIRIS site and my own observations offers the following description: Reclining figure of a fallen infantryman is installed on a long, rectangular pedestal and base. The figure lies at a farm fence in a rocky landscape. There is a polished trefoil, the corps insignia, on the front of the pedestal and a State Seal relief on the left face. It indicates the point from which the regiment drove the Confederates on the afternoon of July 2, 1863. The regiment held the position for about twenty minutes until forced to retire.
The monument was installed in 1888 and dedicated Sept. 11, 1889 by the survivors of the regiment. The monument is composed of: Sculpture: granite; Base: granite with bronze relief. The monument's dimensions are: Sculpture: approximately 50 x 84 x 40 inches; Base: approximately W. 9 feet 6 inches x D. 5 feet 8 inches. The monument was fabricated by J. Henderson Kelley. There are brief inscriptions on all four sides, all of which read:
(Front): 116th Pennsylvania Infantry
2nd Brig. 1st Div. 2nd Corps.
(Back):2nd Brigade.
July 2, 1863
In action 142 officers and men
Killed and wounded 37
(Left):Irish Brigade.
(Right):1st Division.
The 116th Pennsylvania Infantry Monument is a contributing feature to the Gettysburg National Military Park Historic District which is nationally significant under NR Criteria A, B, C & D. Areas of Significance: Military, Politics/Government, Landscape Architecture, Conservation, Archeology-Historic. Period of Significance: 1863-1938. The original National Register Nomination was approved by the Keeper March 19, 1975. An update to this nomination was approved by the Keeper on January 23, 2004. The monument is identified as structure number MN166-B.
From the Nomination Form:
1 of 110 mn in Park honoring PA commands in Gettysburg Campaign. Regiment drove Confederates from this point on pm of July 2, 1863. Located on W side of Sickles Ave above the Loop.
Short Physical Description:
MN & 2 flank markers. Smooth base, 9'6"x5'8"; polished shaft, 8'x4'2" topped w/ sculpture of fallen soldier at farm fence. Shaft has raised trefoil, bronze state & identifying tablets. Flank markers, 1'x1'x1'6", apex top w/ inscriptions on polished faces.
Long Physical Description:
Monument that has two flanking markers. Monument is an 8x4.2 foot polished granite shaft that is topped with a sculpture of a fallen soldier at a farm fence and set on a 9.6x5.8 foot smooth base. The shaft contains raised trefoil, and bronze state and identifying tablets. Designed by J. Henderson Kelly. Flanking markers are apex topped with inscriptions on polished faces, one foot square. Located on the west side of Sickles Avenue above the Loop.
My Sources
1.
NRHP Nomination Form
2.
SIRIS
3.
Stone Sentinels
4.
Virtual Gettysburg
5.
Draw the Sword
6.
Historical Marker Database
7.
Wikipedia