The 140th Pennsylvania Infantry served as a member of Zook’s Brigade in Caldwell’s Division of the Second Corps, Army of the Potomac, A Fighting 300 Regiment. The 140th Pennsylvania Volunteer Infantry served in the Eastern Theater. The regiment was recruited in late 1862, and fought from the Battle of Chancellorsville through the war until the Confederate surrender at Appomattox Court House. It losses during the war were among the highest of any Union regiment. The volunteer regiment was commanded by Colonel Richard P. Roberts (1820-1863). Roberts was a lawyer in Beaver, PA before the war and was killed in action on July 2, here at Gettysburg. Under Roberts' command, the regiment had 590 men engaged at Gettysburg and among them, 37 were killed, 144 were wounded and 60 went missing.
The 140th Pennsylvania Infantry Monument is located on Sickles Avenue, on the right or east side when traveling north. The sculpture is located to the right or east of the very obvious loop at on Stony Hill, just outside of it. 
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 2:43 P.M. I was at an elevation of 561 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 and the SIRIS site offers the following description: Granite monument with bronze trophy of crossed muskets and infantry accouterments on the front. The top of the monument has a pediment shape with bronze state seal. Granite monument has rough hewn sides with a gable top that has brackets on the east side and sets on a 6.6×5.4 foot rough hewn base. Overall height is eleven foot. The monument has a bronze state seal, crossed musket, and infantry accouterments on the east side and inscriptions on the west. Flanking markers have flat tops with inscriptions, one foot square. The monument marks the position where the 52nd New York Infantry drove back, with the Brigade, 1500-2000 Confederates on July 2, 1863.
The monument was erected on August 11, 1885 by the Commonwealth of Pennsylvania. Several of my reliable sources erroneously list the date as 1889. They would be incorrect. The monument is composed of: Sculpture: Gettysburg granite; Base: granite with white bronze plaque. The granite monument's dimensions are: Sculpture: approx. 60 x 50 x 32 in.; Base: approx. 14 x 59 x 41 in. The monument was sculpted by John Flaherty. On the front side of the monument is a narrative tablet which reads:
140th Reg't. Penna. Vols.
Col. R. P. Roberts Commanding.
Zook's Brig., Caldwell's Div., Hancock's Corps.
July 2nd 1863.
(Succeeded 5, Corps Troops.)
Carried into action.
29 officers and 560 enlisted men.
Lost in action.
14 officers and 227 enlisted men.
as follows:Killed, 3 officers and 34 enlisted men.
Died of wounds, 1 officer and 16 enlisted men.
Wounded, 7 officers and 120 enlisted men.
Capt'd and missing, 3 officers and 57 enlisted men.
In memory of our comrades, 1885.
140, P.V.
Right of First Div. 2, Corps.
The 140th 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 MN165.
From the Nomination Form:
1 0f 110 mns in Park honoring PA units in Gettysburg Campaign. Marks general position taken by 140 PA on pm of July 2, 1863 whey they assisted V Corps troops here. Located on E side of Sickles Ave, above Loop & about 400' S of junction w/ Wheatfield Rd.
Short Physical Description:
3'5"x4'11" at base, 6' high. w/ apex top. White bronze (zinc) narrative tablet on S side and relief of trefoil on E & W faces.
Long Physical Description:
Monument that has two flanking markers. Monument is a 3.7 foot square granite shaft topped with a sculpture of regimental accoutrements set on a 6.4 foot square rough hewn base. Overall height is 15.7 foot. The shaft has inscription panels on all sides, and reliefs of rifles and accoutrements as well as a bronze state seal on the east side. Flanking markers are one foot square with apex tops that contain inscriptions. Located on the west side of Sickles at 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.
140th PVI Site
8.
Wikipedia