While on route to the St. Louis area, Confederate General Sterling Price decided to attack the weakly defended post of Fort Davidson at Pilot Knob. Fort Davidson was a small hexagonal earthwork fort defended by Gen. Thomas Ewing, Jr. and his 1,450 Union soldiers. Capturing Fort Davidson would provide arms for Price's 3,000 unarmed soldiers, prevent Ewing's garrison from reinforcing St. Louis or Jefferson City, and provide combat experience for the nearly 6,000 untested Confederate draftees.
Price's leading regiments engaged Union pickets at 1 p.m. on Sept. 26, driving into the town of Ironton. As the rebel strength grew, the small Union force was pushed back toward the fort. During the night, the Confederate army camped south of the fort and prepared to strike the next day.
On the morning of Sept. 27, the Confederates attacked. Two Union regiments fell back from their advance line near Ironton and retreated to the slopes of Pilot Knob and Shepherd Mountains. As the rebels appeared between the two mountains, the siege guns of Fort Davidson opened fire.
The Confederates pressed the attack. Price and his commanders felt that one swift assault would overwhelm the fort. Confederate cannons on Shepherd Mountain fired on the fort as four brigades of Southern troops charged. Union troops still defending Pilot Knob Mountain were engulfed, while those on Shepherd Mountain safely retreated to the fort with the Confederate wave cresting behind them.
Unfortunately for the Confederates, the poor timing of the assaults allowed heavy fire from the garrison to be directed at each attacking brigade. Only one Confederate brigade reached the fort. It advanced one mile under murderous fire, halting only when it reached the fort's moat where Yankees threw hand grenades down on them. The assault was broken. The Confederates fell back to reorganize and prepare for a renewed attack the next day.
Ewing, low on ammunition for his cannons, knew his Union forces could not hold out a second day. He ordered Fort Davidson evacuated. The soldiers silently exited the fort at 2:30 a.m., traveling north past Confederate guards under cover of darkness.
The underground structure was forty feet long, twelve feet high, and twelve feet wide. It was covered with fifteen feet of earth to protect it from enemy fire. Some twenty tons of gunpowder and ammunition were stored here during the battle. At midnight the defenders silently evacuated the fort. Equipment that could not be taken was piled against the magazine and the Union dead were laid nearby. later a party of volunteers lit a fuse to the magazine and galloped for safety. At 3:30 a.m., a small group of soldiers, a party of volunteers, lit a fuse to the magazine and that exploded the fort's powder magazine, destroying the fort's remaining supplies. The startled Confederates did not realize that the fort had been evacuated. General Price presumed that an accident had ignited the magazine and that the fort would surrender in the morning. Ewing escaped Price's pursuing columns, marching 67 miles to the hamlet of Leasburg.
Location below is for Fort Davidson.