James and Stan, here's some excerpts From Wikipedia, the free encyclopedia.
Union engineers commanded by Captain Orlando M. Poe built several fortifications in the form of bastioned earthworks near Knoxville. One was Fort Sanders, just west of downtown Knoxville across a creek valley. It was named for Brigadier General William P. Sanders, mortally wounded on in a skirmish outside Knoxville on November 18, 1863. The fort, a salient in the line of earthworks that surrounded three sides of the city, rose 70 feet above the surrounding plateau and was protected by a ditch 12 feet wide and 8 feet deep. An almost vertical wall rose 15 feet above the ditch. Inside the fort were 12 cannons and 440 men of the 79th New York Infantry.
As a Confederate army under General Braxton Bragg besieged Union forces at Chattanooga, Tennessee, a detachment under the command of Lt. Gen. James Longstreet, a trusted subordinate of Robert E. Lee, was sent to Knoxville to prevent Burnside's Army of the Ohio from moving in support of Chattanooga. After Burnside escaped a trap at the Battle of Campbell's Station, his men took up defensive positions around Knoxville and the Siege of Knoxville began on November 17, 1863. Longstreet determined that Fort Sanders was the most appropriate place to attempt a breakthrough of the Union defenses. He initially planned an assault on November 20, but chose to delay while he received reinforcements. His eventual assault was conducted by three infantry brigades, under Brig. Gen. Benjamin G. Humphreys, Brig. Gen. Goode Bryan, and Colonel Solon Z. Ruff (commanding Wofford's Brigade.
On November 23, 1863, Longstreet's forces seized Cherokee Heights, a tall bluff south of the Holston River (now called the Tennessee River) from Knoxville, but only about 2400 yards (2200 m) from Fort Sanders. Longstreet's original intent was to use artillery to "soften up" Fort Sanders in preparation for a frontal assault; however, at virtually the last minute, he changed the plan to a surprise infantry assault at dawn, hoping that the benefits of surprise would outweigh those of a cannonade. Inexplicably, he squandered the element of surprise by deploying skirmishers forward hours before the assault. Although this movement placed them in good positions for sharpshooting, it clearly revealed his plans to the enemy.
The assault, conducted on November 29, 1863, was poorly planned and executed. Longstreet discounted the difficulties of the physical obstacles his infantrymen would face. He had witnessed, through field glasses, a Union soldier walking across the ditch and, not realizing that the man had crossed on a plank, believed that the ditch was very shallow. He also believed that the steep walls could be negotiated by digging footholds, rather than requiring scaling ladders.
The Confederates moved to within 120-150 yards of the salient during the night of freezing rain and snow and waited for the order to attack. Their attack at dawn has been described as "cruel and gruesome by 19th century standards." They were initially confronted by telegraph wire that had been strung between tree stumps at knee height, possibly the first use of such wire entanglements in the Civil War, and many men were shot as they tried to untangle themselves. When they reached the ditch, they found the vertical wall to be almost insurmountable, frozen and slippery. Union soldiers rained murderous fire into the masses of men, including musketry, canister, and artillery shells thrown as hand grenades. Unable to dig footholds, men climbed upon each other's shoulders to attempt to reach the top. A succession of color bearers was shot down as they planted their flags on the fort. For a brief time, three flags reached the top, those of the 16th Georgia, 13th Mississippi, and 17th Mississippi.
Longstreet called off the disastrous attack after 20 minutes.... Collin Chase.