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 1st New Jersey brigade Monument is located on the right or due east side of Sedgwick Avenue, up a hill and in the woods and south 618 feet shy of the intersection with United States Avenue. The monument is located in a clearing and is exactly 280 feet from the road. I believe this area is called Weikert Hill. 
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 5:19 P.M. I was at an elevation of 547 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: Round columnic sculpture with rough-hewn surfaces contains two relief plaques with portraits of General Philip Kearny and General Alfred T. A. Torbert. It was erected by the State of New Jersey and honors the 1st, 2nd, 3rd, 4th & 15th Regiments. The Brigade actually purchased the entire Weikert Farm to preserve the position it held during the battle (this was, of course, later incorporated into the Park). Consisting of Gettysburg, Quincy, and Hallowell granite, it cost of $5,700.00. Seven feet in diameter, the tall column rises 40 feet. (end Draw the Sword). Basically, my impression of this thing is it looks like an old European castle or tower. There are windows or what look like windows in external relief of the granite (looking like separate piece of granite) containing bronze tablets. The front bronze tablet is contained in what looks like a Greek porch flanked by columns (flat of course). I particularly liked the relief of General Kearney. Surrounding the relief in a circle (bronze) are listed highlights from the General's impressive military career - Mouzaia, Mexico, Solferino, and Chantilly, where he was killed. There are two of these relief portraits and this one has Kearney facing the left (so as to distinguish it from the the one of Torbert which faces the right). The one of General Torbert also contain a circular ring of words cataloging the major battles in which he led the 1st New jersey Brigade including Crampton's Pass, Antietam, Fredericksburg, and Gettysburg. This all makes for a very interesting, unique and imposing tower/monument.
This monument, as well as other New Jersey monuments @ the park, was dedicated on June 30, 1888 by the State of New Jersey . The monument is composed entirely of granite (with some bronze relief plaques) and has the following dimensions: approximately 38 feet in height and 22 feet in diameter. The Bureau Brothers foundry was used for the memorial but I could not recover the name of the sculptor or any other artisans who worked on the project. There are inscriptions on the front and reverse side of this monument which read:
(Front):First Brigade,
New Jersey Volunteers.
Brig. Gen. Alfred T.A. Torbert
1st. 2nd. 3rd. 4th. and 15th.
Regiments Infantry
1st. Brig. 1st. Div. 6th. Corps.
July 2, in reserve, July 3 and 4
detached from the Corps,
held this position.
Erected by the State of
New Jersey, A.D. 1888,
in testimony of the patriotism,
courage and patient endurance
of her volunteer soldiers.
(Back):"Kearny's
New Jersey Brigade"
fought in all important battles
of the Army of the Potomac
from May 1861 to the end of the
war at Appomattox Court House
in 1865. Total Strength 13,805,
including 10th. 23rd. and 40th.
Regiments
New Jersey Volunteers,
which were attached to the
Brigade.
The 1st New Jersey Brigade 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 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