This beautiful, heroic-sized statue is one of 8 statues of historic Civil War figures featured at the Pennsylvania State Memorial. Gregg stands in an especially designed niche on the rear or northeast facing of the gigantic memorial. Each of the four sides has two statues, on either end flanking the arch. There are two on the front and moving to the right or counterclockwise, pass the Hancock (No. 3) and Birney (No. 4) statues and this would be in the rear of the monument, the first position, and left of the arch, statue No. 5 (by my count). The subject mater, General David McMurtrie Gregg (April 10, 1833 – August 7, 1916), was a farmer, diplomat, and a Union cavalry general in the American Civil War.
Gregg was the commander of 2nd Cavalry Division, Army of the Potomac. Gregg was born in Huntingdon, Pennsylvania. He was the first cousin of future Pennsylvania Governor Andrew Curtin (one of the eight statue) and the grandson of Pennsylvania Congressman Andrew Gregg. Gregg was active in state and local affairs and raised funds to preserve Valley Forge as a national shrine. He visited Gettysburg Battlefield numerous times and gave speeches at events. He died in Reading, Pennsylvania, one of the oldest survivors of the war in the state, and is buried there in Charles Evans Cemetery.
The Pennsylvania State Memorial and the Gregg statue are located on Hancock Avenue within a triangular area whose borders consist of Pleasonton Avenue, Humphreys Avenue and Hancock Avenue. The huge Pennsylvania monument faces the southwest. 
There is a dedicated parking area to the rear of the memorial which can accommodate nine cars. Additionally, parking is available on the side of the Hancock Avenue (one way only) in white painted spaces. There is also a rest station with bathrooms and a broken water fountain to the right of the parking lot (this is a one way road). This nearby comfort station was completed in 1933 as the first Gettysburg Parkitecture structure. Please be mindful of not parking on the grass or anything green, lest ye be ticketed. I visited this specific statue on July 5, 2012 and again on August 13, 2012, both times in the late afternoon using a Canon PowerShot 14.1 Megapixel, SX210 IS digital camera and a General Electric A1050 10MP Digital Camera with 5X Optical Zoom for the photos.
The statue is eight feet high and of bronze. Physically, it is a standing portrait of Gregg, resting on a foot high, rectangular plinth with his last name deeply incised on the front. Birney is dressed in a military jacket, 16 buttons up and down his uniform/jacket, a belt with buckle hidden by arms folded at the waist. His proper right hand rests on the hilt of the sword, which points downward, coming to a rest on the plinth. His proper left hand is clasped over the right and he is in a relaxed pose. The sword is positioned slightly to his right (your left). There is a sword strap/belt which looks to be connected somehow to his proper left hip or perhaps tucked under his left arm. He wears riding boots which rise just above the knee, creased in various places. He appears to be leaning backward to the left (his right) with his proper left leg thrust forward, half of his foot extending beyond the plinth (an interesting effect). He gazes slightly to his left or due north, a gazing sentinel. He wears a hat with a wide brim, resting just above the eyes. He has the fullest of beards which extend down to the neck of his jacket and beyond and a relatively trimmed mustache. Overall, the statue is very real with wrinkles in the clothes, detail everywhere and a sense of realism. Gregg appears aged in this statue, not at all a young version of himself as seen on the other statues.
Construction on the memorial began in the summer of 1909. However, at the time of the dedication on Sept. 27, 1910, the eight portrait statues Cottrell (architect W. Liance Cottrell was selected amongst artists who submitted designs) envisioned for the niches on either side of each archway were missing due to the lack of funds. In the year following the dedication, an additional $40,000 as appropriated to create the statues, and the Van Amringe Granite Company as given the contract. The statues were cast at the Gorham Manufacturing Company and were installed in April of 1913 and the entire memorial was rededicated July 4, 1913. The artists specifically responsible for the Gregg statue are sculptor Otto J. Schweizer (1863-1955), Cottrell, W. Liance, architect, Harrison Granite Company, fabricator, Gorham Manufacturing Company, founder and Van Amringe Granite Company, fabricator.
From the SIRIS site: In 1907, $150,000 was appropriated to erect a suitable memorial to honor all Pennsylvanians who participated in the battle at Gettysburg. The design submitted by architect W. Liance Cottrell was selected and the Harrison Granite Company was chosen to execute the design. Construction on the memorial began in the summer of 1909. However, at the time of the dedication on Sept. 27, 1910, the eight portrait statues Cottrell envisioned for the niches on either side of each archway were missing due to the lack of funds. In the year following the dedication, an additional $40,000 as appropriated to create the statues, and the Van Amringe Granite Company as given the contract. The statues were cast at the Gorham Manufacturing Company and were installed in April of 1913. The total cost for the memorial was $200,000.
The Pennsylvania State Memorial (and Gregg Statue) 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 and statues are identified as structure number MN260.
From the Nomination Form:
1 of 19 Civil War State & National Memorial Monuments of the GBMA Era (1863-1895). Built to commerate Pennsylvania officers & soldiers serving at Gettysburg campaign. Designed by 6 sculptors: Samuel A. Murray, J. Otto Schweizer, W. Clark Noble, Lee O. Lawrie, Cyrus E. Dallin, J. Massey Rhind.
Short Physical Description:
Mn is a 4 sided raised pedestal w/bronze tablets (34"x72") listing PA soldiers. Set on 100' sq. base. Arched passages lead to domed interior. Dome is topped w/bronze winged victory. Double bronze statues located in niches on all 4 sides. 4 oversized reliefs adorn the upper observation deck walls.
Long Physical Description:
Monument is a four-sided raised granite pedestal with bronze tablets listing Pennsylvania soldiers and set on a 100 foot square base. It has arched central passages to the domed interior. The dome is topped with a bronze winged victory. Double bronze statues are located in niches on all four sides. Four oversized granite reliefs adorn the upper observation deck parapet walls. A concrete pathway leads from Hancock Avenue to the monument in a Y shape. Designed by W. Liance Cottrell and sculptured by various American artists, including Samuel Murray, J. Massey Rhind, and J. Otto Schweizer. Located on the east side of Hancock Avenue.
Concrete pathway leads from Hancock Ave. to mn in a Y shape.
My Sources
1.
NRHP Narrative
2.
SIRIS
3.
Stone Sentinels
4.
Virtual Gettysburg
5.
Draw the Sword
6.
Wikipedia
7.
Wikipedia
8.
Dcmemorials