The 148th Pennsylvania Infantry served as a member of Cross’ Brigade in Caldwell’s Division of the Second Corps, Army of the Potomac, a Fighting 300 Regiment. The unit was commanded by Colonel Henry Boyd McKeen (1835-1864). McKeen was a local fellow, being a lumber merchant in Camden, New Jersey. At the Battle of Gettysburg, he led his regiment in action in the Wheatfield and Rose Woods on the second day of Battle. When his brigade commander, Col. Edward Cross of the 5th New Hampshire Volunteer Infantry, was mortally wounded in the Rose Woods, he assumed command of the brigade, which he commanded through the rest of the Battle. He remained in command of the brigade (which was the 1st Brigade, 1st Division, II Corps, Army of the Potomac) though the Mine Run Campaign, and the Battles of the Wilderness, Spotsylvania and Cold Harbor. At Cold Harbor, he led his brigade in the fruitless and bloody Union frontal assault on impregnable Confederate positions, and was killed at the head of his command. Today his name is inscribed on the 81st Pennsylvania Monument in the Wheatfield, and on the 1st Brigade, 1st Division, II Corps Marker on Ayres Avenue in the Rose Grove in the Gettysburg National Military Park.
The 148th Pennsylvania Infantry Monument is located along Ayers Avenue at a bend in the road, the top part of an S-shaped turn. The marker is on the right or west side of the road if traveling southwest along the road. To the northeast of this position is Wheatfield Road (T-intersection) and to the south, the Sickles Road intersection, the monument about half way between the two. There is also a large patch of woods which begins (or ends) at this monument location (northeastern part of the woods). This site is also the southeast corner of the Wheatfield, which border is defined on its west side by Ayers Road. 
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 tickete by park police. I visited this monument on Thursday, July 5, 2012 at 12:53 P.M. I was at an elevation of 542 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: Granite monument with trefoil reliefs, four corner columns, cap with relief shields, topped by finial of infantry accouterments, including draped drum and rifle. Flank markers have rough bases 4’11"x2’10"; shafts with trefoil top, 4’1"x2’3". The location of the monument marks the position held by regiment on the afternoon of July 2, 1863.
The monument was erected on September 11, 1889 by the Commonwealth of Pennsylvania. The monument is of granite with some bronze parts. The granite monument's dimensions are approximately 14 ft. 3 in. x 7 ft. 3 in. x 7 ft. 3 in. The monument was fabricated by P. F. Eisenbrown & Sons. There are inscriptions on all four sides which read:
(Front):148th Penna Infantry
1st Brig. 1st Div. 2d Corps.
(Left):The Regiment
engaged the enemy
on this position in
the afternoon of
July 2d 1863.
Present at Gettysburg 468 officers and men.
Killed and died of wounds 2 officers 25 men.
Wounded 5 officers 88 men
Captured or missing 5 men.
Total 125.
(Right):Recruited in
Centre, Clarion, Indiana
and Jefferson Counties.
Organized September 1. 1862.
Mustered out June 1. 1865.
Total Enrollment 1370.Killed and died of wounds, 13 officers, 190 men.
Died of disease, etc. 4 officers 170 men.
Wounded, 28 officers 512 men.
Captured or missing 4 officers 168 men.
Total 1089.
(Back):Chancellorsville. Cold Harbor.
Gettysburg. Petersburg.
Auburn. Strawberry Plains.
Bristoe Station. Deep Bottom.
Mine Run. Reams' Station.
Wilderness. Petersburg.
Spotsylvania. Hatchers's Run.
North Anna. South Side R.R.
Totopotomy. Farmville.
Appomattox.
The 148th Pennsylvania Infantry 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 MN139-C.
From the Nomination Form:
Marks position of 148th Pennsylvania Infantry on afternoon of July 2, 1863. 1 of 110 mns in Park to PA commands at Gettysburg. Located in Wheatfield, W of Ayres Ave. Pos. marker (1901) marks position of regiment on July 3, 1863, located W of Hancock Ave.
Short Physical Description:
Mn, 2 flank markers & 1 position marker. 2 course base, 6'2"x6'3". Shaft 4'7" sq., inscription & corner panels, w/ cross-gable cap & infantry accoutrements. All 14'3" H. Flank markers: rough bases 4'11"x2'10"; shafts w/ trefoil top, 4'1"x2'3". All 6'3" high
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
8.
Find A Grave