The 72nd New York Infantry Regiment mustered in July 24, 1861 and mustered out June 19 to October 31, 1864. At Gettysburg the regiment, which had by this time become noted for its fighting qualities, occupied an advanced position on the Emmitsburg road, which was valiantly defended by the brigade, although finally forced to yield it. The loss of the 72nd: here was 114, and the ranks, which later fought at Kelly's ford, Bristoe Station and in the Mine Run campaign, were sadly thinned. All totaled, the 72nd Regiment lost 11 officers and 150 enlisted men killed and mortally wounded and 1 officer and 88 enlisted men to disease, a total of 250. It is honored as part of the Excelsior Brigade monument at Gettysburg with its sister regiments from the brigade, the 70th, 72nd, 73rd and 74th New York Infantry.
This infantry unit was part of the Excelsior Brigade which served in Humphreys’ Division of the Third Corps, Army of the Potomac. The 70th, 72nd, and 74th Were Fighting 300 Regiments. The 70th New York commanded by Col. John E. Farnum (1824-1870); engaged 371; 20 killed, 93 wounded, 4 missing. 71st New York commanded by Col. Henry L. Potter (1828-1907); engaged 243; 10 killed, 68 wounded, 13 missing. 72nd New York commanded by Col. John S. Austin (1817-1865); engaged 366; 7 killed, 79 wounded, 28 missing. 74th New York commanded by Lt. Col. Thomas Holt (1831-1897); engaged 275; 12 killed, 74 wounded, 3 missing.
The 71st New York Infantry position marker is located in a field at a fence line along Sickles Avenue, on the left or west side of the road if traveling north along the road. To the east of this position is Millerstown Road, to the south, Route 15 and to the west and United States Avenue to the north. This area is called Excelsior Field, near stop 10 of the Gettysburg Driving/Audio tour. The Peach Orchard is just to the southwest of this position. The primary monument for the 
New York Excelsior Brigade (MN184-E) lies 332 feet north (21°) of the position marker. There are a total of five position markers associated with this brigade, all looking exactly the same and no flank markers. The 72nd New York Infantry Position Marker is 237 feet northeast (29°) of the 71st New York Infantry Position Marker and 351 feet northeast (30°) of the 73rd New York Infantry Position Marker. Parking is plentiful and available at intermittently enlarged shoulder cutouts on the right side of the road. Be sure to keep vehicles off the grass or you will be ticketed by park police. I visited the monument on Thursday, July 5, 2012 @ 4:39 PM, EDT & @ an altitude of 581 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, July 2, 1893 (a few sites told me as much but they may have made the same assumption). All the position markers are composed of granite, roughly hewn on the sides, polished and smooth on top, with the incised inscription found on the top. The marker are all 2'6"x1'8"x1'8". Additional details from the nomination form concerning the flank monuments may be found below in red. The inscription reads:
72nd
N.Y.I.
Sickles
Brig.
The New York Excelsior Brigade Monument & 72nd New York Infantry Position Marker 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. Collectively, these monuments are identified as structures number MN178-E.
From the Nomination Form:
1 of 90 mns in Park honoring NY commands in Gettysburg Campaign. Marks position of 5 regiments of NY Excelsior Brigade on July 2, 1863 when it supported US troops on Emmitsburg Rd. Located on W side of Sickles Ave between Wheatfield Rd & US Ave.
Short Physical Description:
Mn & 5 position markers. Pentagon base, 6'2" each side, 21'7" high. Bronze tablets on each side of base, 4'3"x1'10". Bronze tablets on frieze, 5'6" in dia & 1'6" high. Granite domed cap w/ bronze eagle. 2'9" high. Position markers, 2'6"x1'8"x1'8".
Long Physical Description:
Monument that has five position markers. Granite monument is a five-sided base of which each side is 6.2 foot and capped with a granite dome with bronze eagle. Bronze tablets are located on each side of the base and are located on the frieze. Overall height is 21.7 foot. Designed by Theodore Bauer. Position markers are 2.6x1.8 foot. Located on the west side of Sickles Avenue between Wheatfield Road and United States Avenue. Position markers designate the locations of five regiments of the Excelsior Brigade, all west of Sickles Avenue between Wheatfield Road and United States Avenue.
My Sources
1. NRHP Nomination Form
2. Stone Sentinels
3. Virtual Gettysburg
4. Draw the Sword