The 1st, 2nd, 3rd, 4th, and 15th Regiments served as Torbert’s Brigade in Wright’s Division of the Sixth Corps, Army of the Potomac. The 1st, 3rd, 4th, and 15th were Fighting 300 Regiments. The brigade was commanded by Brig. Gen. Alfred Thomas Archimedes Torbert (July 1, 1833 – August 29, 1880). Torbert was a career United States Army officer, a Union Army General commanding both infantry and cavalry forces in the American Civil War, and a U.S. diplomat. After the war, Torbert served in a number of diplomatic posts: as U.S. Consul to El Salvador in 1869, U.S. Consul General in Havana in 1871, and U.S. Consul General in Paris in 1873.
Alfred Torbert drowned off Cape Canaveral, Florida, in the sinking of the S.S. Vera Cruz on August 29, 1880. Eyewitness accounts claimed he swam for over 20 hours. He died on the shore shortly thereafter. His body was recovered August 31, 1880, and he is buried in the Methodist Episcopal Cemetery, Milford, Delaware.
The coordinates for this waymark are for the 2nd New Jersey Infantry Left Flank/3rd New Jersey Infantry Right Flank monument. This monument is a foot from a long stone wall extending down to Sedgwick Avenue at a 45° angle. Both monuments form an intersecting line which ends at 
Sedgwick Avenue, at a 45°. The two monuments are 203 feet away from one another; the 2nd/3rd Monument 225 feet from the road (45°, 159 feet perpendicularly), the 3rd Right Flank 15 feet from the road and 10 feet south or to the left of the Torbert's Brigade Tablet (MN494). 
I guess that means the 3rd New Jersey's defensive line was about 200 feet long and the 2nd & 3rd infantries were shoulder to shoulder on the line. Using the 3rd's left flank marker as a focal point. these monuments are located on the right or due east side of Sedgwick Avenue, south 618 feet shy of the intersection with United States Avenue (perpendicular) and Hancock Avenue (RD310) (which is what Sedgwick turns into). I believe this area is called Weikert Hill. This is where the primary monument for these flank monuments is located, the 1st New Jersey Brigade Monument (MN271-D). 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 5:21 P.M. I was at an elevation of 570 feet, ASL. I used a Canon PowerShot 14.1 Megapixel, SX210 IS digital camera for the photos.
Often, state regiment monuments are also accompanied by secondary monument which designate positions maintained from July 1-3, 1863 as well as flank monuments to delineate the ends of troop lines. Presumably, the position markers were dedicated at the same time as the primary brigade monument, June 30, 1888. The flank marker is composed of granite, smooth on all its rectangular prism sides, and, with the incised inscription found on the slanted top. The marker are all 1' x1'-5" square. Although both markers are eroded and chipped, the Sixth Corps Greek Cross Symbol can still be made out under the incised inscription like an old watermark. Additional details from the nomination form concerning the flank monuments may be found below in red. The inscriptions read:
L.F.
2D
N.J. VOLS.
3D
R.F.
3D
N.J. VOLS.
L.F.
These two flank markers and the 1st New Jersey Brigade Monument are contributing features 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 monuments are collectively identified as structures number MN271-D.
From the Nomination Form:
1 of 12 Civil War Monuments to NJ of the GBMA Era (1863 - 1895). Only one to honor 1st, 2nd, 3rd, 4th, & 15th NJ regiments. Indicates general position held by Brigade Jul 2-3, 1863. Flank Markers denote specific line positions. Vista opened to monument 1902. Located E side of N Sedgwick Ave.
Short Physical Description:
Monument w/ 4 position markers. Base 7'diameter. Coursed, rough-cut shaft w/ decorative banding on turret design. Excised lettering base, minature temple surrounds front bronze tablet. Bronze tablet, back, bas-reliefs sides. All approx. 20' high. Eroded markers, 1' x1'-5" sq.
Long Physical Description:
N/A
My Sources
1.
NRHP Nomination Form
2.
SIRIS
3.
Stone Sentinels
4.
Virtual Gettysburg
5.
Draw the Sword
6.
Historical Marker Database
7.
Wikipedia