My compliments to a detailed and obscure question /picture hint. That is why it is "trivia".
1.
Fort Holt, KY
2.
Lt. George C. Gumbart Commanding Artillery, 2nd Illinois Light Artillery, Battery E
(and/or at different time)
Capt Ed McAllister, Commanding Artillery, McAllister's Battery, 1st Illinois Artillery, (see note sources)
3. 8" Colimbiad was a 64 pounder, the LOC titled "Sketch Plan,Columbiad Battery for Fort Holt" is dated July 18/64 ? after the war ?
https://www.loc.gov/resource/g3954f.cw0220000/
found no nickname ? therefore by research or lack thereof would go with
3.
"James Rifle", Model 1829 32-Pound Siege / Garrison gun rifled by the James method, (Charles T. James)
shot a 64 pound projectile shell, 6.4" bore
Unlike the "Lady Polk / or misquoted Lady Davis" nickname for the exploding gun at Columbus, KY Fort Haleck.

I like all trivia entries with sources and links, as I learn the details of ACW, so here goes, a little long winded
Fort Holt
kyhistory.pastperfectonline.com/webobject/A515E2A1-85DC-414F-BE5D-770139665034http://civilwartalk.com/attachments/4-4-16-jpg.96400/
Fort named for Joseph Holt
January 18, 1861 former Postmaster General is appointed Secretary of War (appointed to both by President Buchanan)
Lincoln removed him for Stanton late 1861, (some sources imply it may have been Holt's suggestion). Holt became Judge Advocate General 1862 - 1865, in late 1864 he declined Lincoln's offer to be appointed Attorney General.
http://www.mrlincolnswhitehouse.org...-generals-and-admirals-joseph-holt-1807-1894/
Fort Holt
(1861 - 1864), Wickliffe (Kentucky)
A Union fort that protected the military depot at
Cairo, Illinois. The actual site has been washed away by the Ohio River.
http://www.northamericanforts.com/East/kywest.html#holt
FRANK LESLIE'S ILLUSTRATED NEWSPAPER, New York, NY, October 12, 1861
FORT HOLT KENTUCKY.
Cairo being the point d'appui of our Western military operations necessitates the establishment of other points to protect it. Hence Cape Girardeau on the north, Bird's Point on the west, Paducah on the east, and Fort Holt on the south. This latter fort is situated on the Kentucky side of the Ohio, and almost immediately opposite Cairo. It is named in honor of that noble Kentuckian, Joseph Holt, who during the short time he held the War Department after the defection of Floyd, endeavored to repair the damage caused by his fraudulent predecessor. Our readers will perceive that Fort Holt is rapidly becoming as impregnable as Cairo, which city it at once protects and is protected by. With Fort Holt and Paducah in our possession, troops can be thrown into any part of Kentucky to crush Secession and assist the Unionists. Our larger picture represents the troops landing on the Kentucky shore to commence the building of Fort Holt. The rapidity with which they have proceeded with their arduous task reflects the highest credit on their industry and skill.
NOT to be confused with
Battery Holt near Cincinnati, f/k/a Three Mile Creek and Licking Point Battery
http://www.cincinnaticwrt.org/data/ohio in the war/1862 Defense of Cincinnati/iv_defenses.pdf
Stationed at Fort Holt
2nd Illinois Light Artillery, Battery E
Lt. Gumbart Commanding Artillery
"The Battery, ( E ) Lieutenant Gumbart commanding, moved to Cairo, September 14th; moved to
Fort Holt and Jefferson, Ky., and then returned to Cairo. On November 1st, Lieutenant Gumbart's section went on an expedition to Bloomfield, Mo., and January 9, 1862, to Columbus, Ky., and returned."
http://civilwar.illinoisgenweb.org/history/a-002-lt.html
Stationed at Fort Holt
1st Illinois Artillery, Battery D
Capt Ed McAllister, Commanding Artillery, McAllister's Battery,
for a short period prior to engagement at Fort Henry
https://books.google.com/books?id=CnYVAQAAMAAJ&pg=P***0&lpg=P***0&dq=commander+fort+holt+battery+civil+war&source=bl&ots=3IybdYY2fA&sig=4NAhPFHQVMfxISVtK2ZvOJtU97I&hl=en&sa=X&ved=0ahUKEwi8tYef3fXLAhUBqx4KHeF4CT84ChDoAQgnMAI#v=onepage&q=commander fort holt battery civil war&f=false
"The regiment (7th IL Infantry) went into winter (1861) quarters at Fort Holt, Ky.,
Colonel Cook commanding Post. The garrison consisted of a brigade - Seventh and Twenty-eighth
Illinois and
McAllister's battery. General Grant commanded the District of Cairo."
"By April 1862 both of these forts (Jefferson & Holt) were deserted. Fort Holt having been flooded out in the spring. Federal forces in far western Kentucky concentrated at Columbus and Paducah." Ft. Jefferson (& Holt)
Historical Marker Text, Fort Jefferson, Wickliffe, KY
"By late September 1861, there were 3,595 federal troops in Fort Holt and more than 2,000 at Fort Jefferson. Refugees, mostly former slaves, flooded Union lines soon after the forts were established. They were put to work by General Grant on the fortifications at Fort Holt and worked felling trees and digging earthworks.
"Troops from Fort Jefferson and Fort Holt were sent to Elliott's Mill and involved in skirmishes and reconnaissance in late September 1861. Fort Holt troops later went on a September 26 raid on Blandville and arrested secessionists on September 26. All troops from Fort Holt went with General Grant and fought in the Battle of Belmont.
"Most of the troops from Fort Holt and Jefferson accompanied General Grant to Forts Henry and Donelson as the western theatre moved east and south. On January 10, 1862 Federal troops were sent to Fort Jefferson as a diversion to distract Confederates at Fort Henry and Donelson.
64- pounder James Rifle, , a model 1829 32-pounder rifled using the "James" (Charles T. James) method
used a 64 pound "shot" which was a projectile developed by James using his birdcage method "James pattern solid shot"
A James pattern solid shot. The "birdcage" at the base would have been covered by sheet lead which, upon firing the gun, would have expanded into the grooves of the rifling.
http://www.civilwarartillery.com/projectiles/halfshells/IIA9.htm
Edit - It appears that Lt. Gumbart commanded a battery at Fort Holt at one time, but not the battery that included the 64-pounder. "James Rifle" would be the generic name of the gun, but not the nickname by which this particular piece was known.
Hoosier