The 1st Company, Andrews, Massachusetts Sharpshooters was also known as Andrews’ Sharpshooters. During the battle of Gettysburg, it served as a member of the Second Corps, Army of the Potomac. The company of sharpshooters was organized in Lynnfield, Massachusetts and mustered in on September 2, 1861 and mustered out on September 6, 1864[. The unit was commanded by Captain William Plumer (November 29, 1823 - December 4, 1896). Plumer was a graduate of Harvard University and lawyer in Lexington. Due to wounds received in June 1863, he rode to Gettysburg in an ambulance. Yet, another source (obituary) states he received a wound at the battle of Gettysburg, which caused him to leave the service. Capt. Plumer took great interest in all town and political affairs, and for many years was chairman of the democratic town committee. Under his command, the Sharpshooters had 50 men engaged at Gettysburg and among them 2 were killed, and 6 went missing.
The 1st Company, Andrews, Massachusetts Sharpshooter Monument is located on the left or west side of 
Hancock Avenue (RD310) if traveling north along the road, north of the Angle. There is a 3-inch Ordnance Rifle to the left (if facing west) pointing west, or a few feet south of the monument. The rifle is marked on the muzzle as registry no. 489 and represents the weaponry used by this unit. The 14th Connecticut Infantry Monument (MN217-F) is 60 feet north of this position and the gigantic Major General Meade Equestrian Statue (MN690) is northeast across the road, 206 feet away. The monument is 442 feet north of the High Water Mark Monument (MN230) and Copse of Trees and 658 feet due south of the Abraham Brian Barn. The monument faces due east, so on would have to face west, in the direction where the final Rebel attack originated on July 3, 1863. This area is an absolute beehive of activity as this site represents the best of what Gettysburg has to offer, both historically and monumentally. Parking is plentiful and is available road-side at intermittently enlarged shoulder cut-outs, usually marked with white striping. Be sure to keep vehicles off the grass or you will be ticketed by park police. I visited this monument on Tuesday, August 7, 2012 at approximately 5:19 P.M. I was at an elevation of 620 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: A stone stele composed of pieces of marble is adorned on the front with a relief depicting the profile of a sharpshooter as he about to pull the trigger on his rifle. He holds the rifle up with his proper left hand and rests his proper right hand on the trigger. Monument is a Carrera marble shaft on a 4.10×1.10 sandstone foot base. The shaft has an excised sculpture and an incised inscription. Overall height is 4.8 feet.
The monument was dedicated on April 1, 1886 by the Commonwealth of Massachusetts. The relief sculpture is composed of marble and the base is of red slate and has the following dimensions: The sculpture is approximately 7 feet x 4 feet 10 inches x 1 foot 10 inches and the base is approximately 1/2 foot x 5 feet 1 inches x 3 feet 8 inches. The monument was sculpted by Fred M. Torrey (1884 - 1967). There is a brief inscription incised on the marble which reads:
1st. Andrew
Sharp-shooters.
Unattached Mass. Vol.
in action
July 3rd. 4th. & 5th. 1863.
in different positions.
In God we put our trust.
But kept our powder dry.
The 1st Company, Andrews, Massachusetts Sharpshooters 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 MN218-A.
From the Nomination Form:
1 of 9 Mn to Sharpshooters. Erected 1886. Indicates position held July 3, 1863. Located W side Hancock Ave N of Angle. Positiion Marker in Ziegler Woods shows location Jul 2, 1863. Cannon to L of Mn included in entry.
Short Physical Description:
Mn & Position Marker. Mn: 4'10"x1'10" sandstone foot base. Solid Carrera marble shaft w/ excised sculpture, incised inscrip. All 4'-8"H. Position Marker 1'-2"sq x 2'-8"H w/aluminum tablet (1913). Mn eroded, inscrip very faint.
Long Physical Description:
Monument that has position marker. Monument is a Carrera marble shaft on a 4.10x1.10 sandstone foot base. The shaft has an excised sculpture and an incised inscription. Overall height is 4.8 feet. Position marker is 1.2 foot square and 28 foot high with an aluminum tablet (1913). Monument is located on the west side of Hancock Avenue north of the Angle. Position marker is in Ziegler's Grove.
My Sources
1.
NRHP Nomination Form
2.
SIRIS
3.
Stone Sentinels
4.
Virtual Gettysburg
5.
Draw the Sword
6.
Historical Marker Database
7.
Obituary
8.
Antietam on the Web