When General William Rosecrans took command of the Fourteenth Corps (which would become the Army of the Cumberland), he recognized the need for engineering resources. The Army’s orders required campaigning across rough terrain and crossing several water-courses. Lacking a standing body of dedicated engineers, Rosecrans required the line infantry units to provide fatigue details for the engineering tasks.
Rosecrans’ chief engineer, Captain James St. Clair Morton, directed the detailed troops to tasks such as bridge repairs and road improvements through November and December. These troop details became a Pioneer Brigade under the command of Morton. Three battalions of infantrymen turned into engineers, supported by the Chicago Board of Trade Battery under Captain James Stokes, made up this Pioneer Brigade. The intent was for these pioneers to work building bridges, improving fords, building entrenchments, and generally performing other tasks with the shovel while the Army was on the move. But when battle neared, the details would return to the line commands.
That plan worked fine as Rosecrans directed his army out of Nashville in the closing days of December 1862. In his official report on the battle of Stones River, Morton noted the brigade constructed two bridges over Stewart’s Creek on the eve of battle. On the morning of December 31, the brigade’s task was to improve McFadden Ford on Stones River in support of Rosecrans’ planned move on Murfreesboro. But this move came to a halt with the Confederate attacks on the right side of the Federal lines.
After preliminary work at the ford, Morton’s Pioneers moved to a reserve position along the Nashville Pike. The flow of battle soon placed the engineers the most critical point in the most critical phase of the battle. Instead of working the spade or repairing some bridge, the infantrymen turned engineers were called upon to use the musket. Instead of returning to their respective line units, the pioneers fought as a line unit,
At some point during the action, the Pioneers constructed basic earthworks to protect access to the Nashville Pike. Some of those works are there today.
Morton’s pioneers remained in the fight for the next two days, alternating between roles of infantry and engineer. Stokes battery, which remained in support much of that time, fired 1,450 rounds – a total surpassed by only three other batteries engaged in the battle.
There is a ready comparison, favorable on both counts, regarding the battlefield performance of engineers at Fredericksburg and Stones River. At Fredericksburg, a designated, organic engineer brigade enacted a river crossing under fire. At Stones River, a task force of infantrymen detailed for work as engineers performed combat engineering on the battlefield. No longer was the engineer soldier expected to toil behind the front lines, working a sweat but not exposed to enemy fire. Engineers were now combat troops directly augmenting the combat arms in the battle.