The 2nd Corps, 1st Division, 3rd Brigade was also known as Zook’s Brigade. During the battle of Gettysburg, it served as a member of Caldwell’s Division in the Second Corps, Army of the Potomac. The brigade was commanded by Samuel Kosciuszko Zook (March 27, 1821 – July 3, 1863). Zook joined the N.Y. militia in the 1850's, at the same time becoming a pioneer in telegraphy. He eventually became superintendent of the Washington and N.Y. Telegraph Company & was Lieutenant Colonel of the 6th N.Y. State Militia when the war began. After the three month term of the militia expired in October of 1861 he became colonel of the 57th N.Y. Infantry Regiment . He fought in the Peninsula, but missed Antietam due to medical problems. At Fredericksburg, Zook took his brigade as far as any in the attack on Marye's Heights, earning him promotion to brigadier general. On July 2, 1863, the second day of the Battle of Gettysburg, Brig. Gen. John C. Caldwell's division, including Zook's brigade, was sent to reinforce the crumbling III Corps line that was being assaulted by the Confederate corps of Lt. Gen. James Longstreet. Zook was directed by one of the III Corps staff officers toward the Wheatfield to reinforce the brigade of Col. Régis de Trobriand & to fill a gap near the Stony Hill. Zook, on horseback, led his men up the hill, which attracted the attention of men from the advancing 3rd and 7th South Carolina Infantry regiments, of Joseph B. Kershaw's brigade. He was struck by rifle fire in the shoulder, chest, and abdomen, and taken behind the lines for medical treatment at a toll house on the Baltimore Pike. He died from his wounds on July 3 and is buried near the grave of General Hancock in Montgomery Cemetery in West Norriton Twp, PA. He received a brevet promotion to major general for Gettysburg, awarded as of July 2. The 
Brigadier General Samuel Zook Marker (MN168) was erected to commemorate his death & is located near Wheatfield Road, @ the north edge of the Wheatfield.
The Zook's Brigade Monument is located on the right or north side of Sickles Avenue while traveling northwest to west at The Loop. The Loop (aptly named considering the road looks like a teardrop) actually begins at this monument and it is here where there are a cluster of these things. Twenty-six feet to the right or southeast of this tablet is the 66th New York Infantry Monument (MN155) and another 40 feet away to the right or southeast of that monument is the 5th Michigan Infantry Monument (MN154). Next to the Michigan monument, about 4 feet away is the 32nd Mass. Infantry Field Hospital Monument. Finally, 92 feet due south of this monument & directly across the road is the Irish Brigade Monument (MN156-A). There is also a trail here at the Zook monument which leads up the hill to the top of The Loop (instead of looping around) where there is many more monuments. The area is also very heavily wooded. Parking is available along the side of the road at intermittently enlarged shoulders BUT NOT HERE. Your best bet is to go around The Loop and park up there and walk down the trail to see the monument. Take care to park on asphalt-widened shoulders & not on anything remotely green looking as Park Police will happily ticket you. I visited this site on Monday, July 1, 2013 on the 150th anniversary of the Battle of Gettysburg @ 5:50 PM, EDT & @ an altitude of 529 feet, ASL. As always, I used my trusty and oft abused Canon PowerShot 14.1 Megapixel, SX210 IS digital camera for the photos.
The monument was completed under the direction of the Gettysburg National Park Commission (established by the United States Department of War), after they took over the administration of the park from the Gettysburg Battlefield Memorial Association (whose funds had expired) on March 3, 1893, and whose stewardship was then transferred to the National Park Service in 1933) SOURCE. According to the NRHP narrative, this monument was built in 1911 but finished in 1912. I can't resolve if the 1912 date represents a completion of the physical construction of the tablet or collectively all 75 tablets. Another source wrote the last of the Confederate Brigade tablets were completed in December 1910. One would think the Union tablets would have been completed before the C.S. tablets.
These battery tablets were cast by Calvin Gilbert. Gilbert joined the 87th PA Volunteers when the "Rebellion" broke out. Since he was musically inclined, he was made a member of the regimental band. In early 1863, he was promoted to the rank of Captain and sent to Washington D.C. for commissary duty. He served in that capacity until the war ended in 1865, and at war’s end earned the brevet rank of Major. 
After returning home to Gettysburg, Major Gilbert moved his family to the town of Chambersburg, where he served as the Superintendent of Schools. He also opened an iron foundry there in 1868. When Calvin learned, nearly thirty years later, in 1894, that the Gettysburg Foundry was available, he purchased it with a business partner & moved his family back to Gettysburg. For the next twenty years, the Calvin Gilbert Foundry created ironworks that are still seen today on many historic forts and national battlefields (this tablet), from upstate N.Y. to Florida to Lookout Mountain. Gilbert lived to be 100 years old & attended the Last Reunion of the Blue and Gray for the 75th anniversary of the Battle of Gettysburg when he was 99. He was a most remarkable man and lived an amazing life.
There is an excellent excerpt in the American Guide Series about Gilbert attending the 75th reunion anniversary.
Look carefully on the reverse side on a few of these tablets and his name might be there; I found a tablet or two like this. The inscription on the monument reads:
Army of the Potomac
Second Corps First Division
Third Brigade
Brig. Gen. Samuel K. Zook
Lieut. Col. John Fraser
52d. 57th. 66th. New York
140th. Pennsylvania Infantry
July 2 Arrived early in the morning and formed on right of Second Brigade on line from Cemetery Hill to Round Top. Between 5 and 6 p.m. advanced with Division to left and entered the Wheatfield and the woods on its right in line of battle forcing the Confederates through the field and the woods to the further end. Brig. Gen. Zook fell mortally wounded in this advance the Brigade being on the right of Division it extended to an open field on the west. The line of Third Corps on the Emmitsburg Road having been forced back and the Division having been flanked by superior forces on its right and left the Brigade retired with the Division and resumed position in line with Corps.
July 3 Constructed entrenchments and held the position until the close of the battle.
Casualties. Killed 7 officers 42 men. Wounded 18 officers 209 men. Captured or missing 4 officers 78 men. Total 358.
There are hundreds of non-sculpted monumentation for the various C.S. & Union units which fought at Gettysburg. There are about 10 different variations of tablets, markers and monoliths by my reckoning. Six designs represent brigade (2), division (2), corps (2), & army headquarters (2), each different in a subtle way so as to distinguish between armies. Battalion/ battery / advance position markers and regimental monuments for United States Regulars & Confederate have their own distinct design (2), bringing the total to ten designs at the battlefield. The bronze tablets (the brigade monuments) were created by Albert Russell & Sons Co. of Newburyport, Mass.. The granite bases which accompany the various tablets were created by the Van Amringe Company out of Boston, Mass. The cast iron tablets were of course manufactured by the aforementioned Calvin Gilbert. The 1910 Gettysburg Commission report lists the awarded contracts to these companies (not Gilbert) for the tablets.
All of these tablets were designed by architect Colonel Emmor Bradley Cope (July 23, 1834 - May 28, 1927). He designed pretty much every tablet for both the Union and Confederate armies, each one distinct, with several different varieties. He is buried in Evergreen Cemetery in Gettysburg, as well he should be as this park and most of the things seen here today were designed by him and as such, are his legacy.
On October 1, 1898, the Gettysburg National Park Commission in a letter to the Secretary of War gave recommendations for continuing the task of organizing & progressing the work of the GNMP. Each November they wrote their annual report which outlined the work of the GNPC for that year. The following is an excerpt from that report relevant to this waymark. The link at the end of the ¶ will take you to the entire report. The method of marking the positions of troops on this field, as approved by the War Dept., is to place the principal tablet or monument of each command at the position occupied by the command in the main line of battle, & to mark the several important positions subsequently reached by each command in the course of the battle by subordinate and ancillary tablets, with appropriate brief inscriptions giving interesting details and occurrences & noting the day & hour as nearly as possible. SOURCE
Most of the Commission reports have been digitized and can be found HERE.
Information about these specific types of monuments:
BRIGADE HEADQUARTERS MARKERS (FOR UNION & CONFEDERATE TABLETS)
The Brigade Headquarters (& Confederate artillery battalions, equivalent to Union artillery brigades) are bronze tablets mounted at an angle on a stone pedestal & describe the movements & itinerary of each memorialized unit. Union headquarters have rounded tops and square bases. C.S. headquarters have flat tops and round bases. Union headquarters are marked with their corps or service branch symbol (like a cross, clover or crescent moon), while Confederate headquarters are simply labeled "C.S.A.". There are seventy-four brigade markers at Gettysburg honoring the Union's various brigades. (Other sources say there are seventy-five). There are sixty-four brigade markers honoring the Army of North Virginia's various brigades. The Union Brigade tablets consist of sea-green granite with a square 36” x 36” base; they weigh 3500 pounds. On each pedestal is mounted a bronze tablet w/ rounded corners weighing 300 pounds. They were built by Albert Russell & Sons Co. of Newburyport, Massachusetts and Charles Kappes. The C.S. Brigade tablets consist of red circular Maine granite bases 34 1/2 inches diameter and weighing 3,000 pounds. On each base is mounted a 300 pound bronze tablet. They were built by Van Amringe Granite Co. (pedestals), Albert Russell & Sons Co., Newburyport, Mass (tablets) and Charles Kappes (foundations).
The Zook's Brigade Tablet is a contributing feature to the Gettysburg Nat'l Military Park H.D. which is nationally significant under NR Criteria A, B, C & D. Areas of Significance: Military, Politics/Gov't, Landscape Architecture, Conservation, Archeology-Historic. Period of Significance: 1863-1938. The monument is designated as structure no. MN472.
From the Nomination Form:
1 of 75 Civil War US Brigade Tablets in Park. Records movement of Zook's Brigade during Battle of Gettysburg, July 1-3 1863.
Short Physical Description:
Bronze inscription tablet, 4”0’ x 3’8”, attached to slant face of polished sea green granite monolith. 3’0” squared base of monument tapers to a smaller dimension at the tablet. All 5’4” H.
Long Physical Description:
Located on Sickles Avenue, east of the Loop near Wheatfield
