Lieutenant Samuel Benjamin’s Report on the Union Artillery at the Battle of Fort Sanders

In September 1863, Union forces under Major General Ambrose Burnside occupied Knoxville, Tennessee. Union Army engineers immediately set about the task of constructing a defensive line of earthworks and other fortifications. One of these fortifications along the line just to the west of town was Fort Sanders.

While Burnside was occupying Knoxville, General Braxton Bragg’s Confederate army defeated Major General William Rosecran’s Union army at the Battle of Chickamauga in northern Georgia. Rosecran’s army retreated to Chattanooga, and Bragg placed that city under siege. With a sizable union force approximately 100 miles to the northeast, Lieutenant General James Longstreet’s Corps was ordered to march to Knoxville and eliminate any possible threat from Burnside. Longstreet’s Corps had been temporarily detached from the Army of Northern Virginia to reinforce Bragg, and had played a major role in the Confederate victory at Chickamauga.

Longstreet arrived in the Nashville vicinity in mid November. The Federals were well entrenched by this time, and the Confederates looked for an area in the defenses that was suitable for an assault. It was determined that Fort Sanders, despite its formidable structure and defenses, was the most likely point where the Union line could be breached. Due to the topography at and around Fort Sanders, Confederate forces could approach the works from the northwest and get to within 200 yards without being seen. The Confederate command believed that if Fort Sanders was captured, the road into Knoxville would be wide open.

On November 29th, Longstreet attacked Fort Sanders with three brigades. Though only about 440 men were in Fort Sanders, supporting infantry and artillery had been skillfully deployed and provided excellent and deadly supporting fire. The storming brigades had difficulty scaling the steep walls of the fort, and Federal fire cut them down quickly. Between the excellently engineered defenses and Union artillery and rifle fire, the attack had no chance of success. The assault was over in about 20 minutes. No follow up attempts at breaking the Union lines were made.

Assault on Fort Sanders by Kurz and Allison

Assault on Fort Sanders by Kurz and Allison

The officer in charge of the Union artillery at Knoxville was Lieutenant Samuel N. Benjamin of the 2nd U.S. Artillery. A regular army West Point graduate, Benjamin was a veteran of several campaigns dating back to First Bull Run. Benjamin belatedly filed a report about the artillery at Fort Sanders in December 1864. He sent it to Burnside, who at the time was at home awaiting orders after the debacle at the Battle of the Crater outside Petersburg, Virginia in July of 1863:

December 20, [1864.]
Major-General BURNSIDE,
U. S. Army:

DEAR GENERAL: Inclosed you will find an account of the siege of Fort Sanders, giving the plan of the defense and a description of the assault. It is miserably written, but I had to hurry it, as I am very busy, and could hardly get time to write at all; so please excuse mistakes and all deficiencies. The whole affair lasted full three-quarters of an hour, and the actual fight at the ditch and on the parapet over twenty minutes. During the flag of truce I talked with many officers, among them Lieutenant-Colonel Alexander, chief of artillery on General Longstreet’s staff, who spoke highly of our maneuvering at the battle of Campbell’s Station.

I claim credit mainly for building up the work, getting it properly garrisoned, and, above all, for drawing the attack on the northwest salient. If the assault had been made anywhere else it would have succeeded. During the assault I handled the troops, giving all orders and seeing to their execution.

The greatest credit is of course due to the men, who fought splendidly. I saw one man use an ax.

I put my pistol within 6 inches of a rebel’s face and pulled trigger three times. They were on the exterior crest of the parapet all the time.

Wishing you success and happiness, and hoping that you may have a command soon,
I remain, very respectfully, your friend,
Captain, Second Artillery.
On the morning of November 17, 1863, in accordance with orders, I posted Gittings’ battery near the depot; Roemer’s at Seminary Hill; Buckley’s and Benjamin’s on the ridge to the northwest of the town, about 1 mile out and north of the main road to Campbell’s Station. Here a bastion work (square) had been commenced, and was about one-fourth finished on three fronts–fourth front not commenced. It afforded no protection, nor could a gun be dragged into it until four hours’ work with 200 negroes had made ways and cleared places for them. I assumed command by your order, and planned the defense.

The line held by our troops made a right angle here, with the fort at the angle. The northwest bastion being the salient of the angle, following its capital less than 80 yards from the fort, was an abrupt descent, running into a large thick wood; the descent covered with a thin growth of pines.

By dint of persuasion, and demonstrating the impossibility of holding this position otherwise, I prevailed on General Ferrero to occupy the hill due south from the fort, on the other side of the road to Campbell’s Station. (Fire from that point would have taken much of our line in reverse.)

The northwest bastion was the point to attack, if the rebels could be induced to attack the earth-work instead of the low breastwork or rifle-pit thrown up by the men.

Lt. Samuel Benjamin

Lt. Samuel Benjamin

At the fort were four 20-pounder Parrotts, four light 12-pounders, and two 3-inch guns (Buckley’s other two guns I placed on the hill to the south). I left the fort open in the rear, the rifle-pits running from the ends of the gorge south to the river and east up by the town. I procured the Seventy-ninth New York Volunteers for garrison (about 125 strong), and in case of attack on the fort four companies of the Seventeenth Michigan were to enter it and post themselves at the point assaulted. I placed the guns so as to sweep thoroughly all approach to the rifle-pits, leaving a large section without fire in front of the salient of the northwest bastion to induce them to assault there. Work went on night and day under my sole direction. The engineer officers of the corps being occupied on other parts of the line, no assistance or advice was asked or received, except I altered a portion of their rifle-pits so as to contract the line and not be forced to fire over our own men. The first day of the siege, before the enemy had closed in, I dug two lines of pits for the pickets, about 80 and 30 yards from the fort–the second line to rally in if driven from the first.On the 20th instant, at my request, the Seventeenth Michigan made a sortie in the night, driving the enemy’s pickets and burning a house which they occupied. The rebel sharpshooters were very annoying, causing casualties in the fort every day. I stuck brush in the parapet, along the interior crest, so as to screen us from sight, and enable us to look out without being seen. I also covered the embrasures with bags and barrels, so arranged as to see out without being seen.

On the 21st, the enemy had a parallel about 300 yards off, half enveloping the northwest bastion. General Ferrero had now taken up quarters in the fort, in a small bomb-proof, built for telegraphic operations.

On the morning of the 23d, the attack on the enemy’s parallel was made. This attack I strongly opposed.

On the 25th, a battery was discovered on the other bank of the Holston, 150 feet above us (six guns), commanding and having a view of all in the fort. They also had on west front an embrasure battery of six 12-pounders and one 20-pounder Parrott; on north front, embrasure battery of two 20-pounder parrotts, same two 3-inch guns, two other two-gun batteries, caliber unknown (probably 3-inch). These varied from 700 to 1,500 yards in distance from us–the one across the river 2,500 yards. Every man in the fort had his place assigned him, and ate and slept at his place, so, on an alarm, they only rose and crouched by the parapet. At night 1 man in 4 was awake, 2 officers and 2 non-commissioned officers, besides the regular guard on picket. On an alarm, each man then up woke the three sleeping near him; thus the garrison was at once ready for an attack. I made an embrasure in such manner that, by taking out a few shovels of earth, I could train a gun on the northwest bastion, sweeping its ditch and parapet. The parapet there was strengthened. The whole fort was well fitted with traverses to protect our men, as the enemy had a reverse and enfilading fire on each front. In front of the northwest bastion I made an abatis, concealed from the enemy by a small rise of ground, and inside of the abatis a little entanglement of telegraph wire. We worked night and day, but still at many places we went out and in the fort over the parapet and through the shallow ditch. The work was now known as Fort Sanders, and was very weak, and should have fallen by the ordinary chances of warfare; but the garrison were picked men. We had many alarms and exchanged shots from time to time with the enemy.

About 10 p.m., November 28, the enemy captured most of the outer line of pickets, and drove the others into the fort. Skirmishing and firing continued for two hours; at the end of which time we had not a picket 20 yards out from the fort, and the enemy had secured the crest of the ridge which the work was on, beneath which they could mass troops night or day, within 80 yards of the work, without our knowledge. In spite of the opposite opinion held by most, I prepared for an attack at daybreak.

Fort Sanders Vicinity Map

On the 29th, I rose early, roused and warned all the men, and had every one posted, watching for the attack. A little after 6.30 a.m. the enemy opened furiously on the fort, with over twenty guns, and also swept the parapets and rained through the embrasures a heavy fire of musketry from the crest of the ridge 80 to 100 yards off. I went about the fort enforcing strict silence, and seeing that the men were kept close against the parapet, ready to rise and fire. So well had I protected the fort with traverses, and also owing to the fog making it quite dusky, no one was hurt by this fire except one cannoneer. In about twenty minutes the cannonade slackened somewhat, and the musketry fire was directed on the northwest bastion: at the same time a heavy column charged on a run from under the ridge upon the salient of bastion (five regiments formed the column–as near as I could judge, “Column by division closed in mass”). The guns were triple-shotted with canister, but only one got a shot at them, as they came up through the sector without fire. They burst through the abatis, and although great numbers fell flat in the entanglement, the weight of the column carried them promptly over it. They lost many at the entanglement, and in less than two minutes from their appearance, they were in the ditch, attempting to scale the parapet. As they endeavored to surround the fort, the two guns in the bastion poured triple rounds of canister in their faces (not 10 yards from them), and I soon had the flank gun firing through the ditch and across the salient. They climbed the parapet continually, but only to be shot as they gained the top, the men being ordered to fire at none except those on the parapet. I also threw shells with my own hand in the ditch, to explode among them. After a while they began to fall back, but another column coming up, the assault was pushed more savagely than ever, and three of their flags were planted in our parapet. At length they again fell back in great confusion to the ridge from which they charged, leaving the ground strewn with dead and dying and three colors in our possession.

Confederate Assault on Fort Sanders

We took over 250 prisoners unhurt, 17 of them commissioned officers (we were not 250 strong in the fort); over 200 dead and wounded lay in the ditch, among them 3 colonels. One-half in the ditch were dead; most of the others were mortally wounded. We also got over 1,000 stand of arms. The prisoners in the ditch represented eleven regiments, and estimated their regiments at about 400 strong, each.

From what I learned from their officers and from what I saw, I gathered the following plan of assault: Two brigades to watch and fire on our lines, one brigade to assault, and two more to support it. Two brigades came up to the ditch. The party actually engaged in the assault numbered about 4,000 men, not including reserves. Of these they lost from 1,300 to 1,500 killed, wounded, and prisoners; a very large proportion killed, and a large number mortally wounded.

In the fort we lost 13 men, 8 killed and 5 wounded.

General Ferrero was in the little bomb-proof, and I did not see him outside, nor know of his giving an order during the fight. The capture of the fort was to have been at once followed by a general assault on the town, their whole army being in readiness.

Lieutenant, Second U. S. Artillery.

Actual Confederate losses in the assault were closer to 800 rather than Benjamin’s figure of 1300, but the battle was an overwhelming Union success.  After learning of the Federals’ successful attacks on Lookout Mountain and Missionary Ridge at Chattanooga on November 25th and 26th, and knowing that Union reinforcements were on the way,  Longstreet began withdrawing to the east on December 3rd and 4th.

There is an interesting side note about General Edward Ferraro, whom Benjamin wrote “was in the little bomb-proof, and I did not see him outside, nor know of his giving an order during the fight”. Ferraro was reprimanded for doing the same thing during the disastrous assault at the Battle of the Crater, the same battle that essentially ended Burnside’s military career (he was never given another field command).


“The Defense of Knoxville” by Orlando M. Poe. In Battles and Leaders of the Civil War, Volume 3, edited by Robert U. Underwood and Clarence C. Buel

“Longstreet at Knoxville” by E. Porter Alexander. In Battles and Leaders of the Civil War, Volume 3, edited by Robert U. Underwood and Clarence C. Buel.

Official Records of the Union and Confederate Armies in the War of the Rebellion, Series 1, Part 1, Volume XXXI.

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