WE HAVE BEEN ASKING THE WRONG QUESTION.
Instead of " passing out ammunition " it is the
THE PASSAGE OF LINES UNDER FIRE
That is the relevant line of inquiry.
The passage of lines under fire has been an essential element of maintaining initiative & tempo for centuries.
Roman cohorts deployed with the passage of lines as an integral element. The rearmost lines consisted of the most experienced & steady fighters. In both advance & defense, the best men could move to where they could have the greatest impact.
Hand to hand combat is physically exhausting. It was the legionary doctrine of the passage of lines bringing fresh men to the front that made it possible for Romans to overcome much larger opponents.
Romans attacked in a triangular formation. The point made first contact. Each successive line relieved the one in front & secured the flanks of the formation. At the point of attack, defenders were faced with line after line of fresh fighters.
It isn't hard to imagine the effect of several simultaneous triangular attacks on an opponent's line of defense.
In the context of the Civil War, in order to maintain initiative during a battle a passage of lines under fire was essential.
The of passage of lines under fire in the fight for the Round Forest on December 31, 1862 during the Battle of Stones River is the example I am most familiar with.
The Round Forrest copse of trees was the key to the 14th Army Corps position. It was on the right flank of Bragg's line that reached three miles to the west from there. The attackers were in General Polk's corps.
The famous flank attack was taking place miles away on the other side of the cedar break on the western edge of this map.
An important feature of the battle space is the sunken Nashville & Chattanooga RR road bed. It was a ready made trench line.
As at Shiloh, Bragg's left under Hardee was expending itself fighting on ground with no tactical significance. It was physically impossible to shift the focus of the attack onto critical Round Forest.
What isn't obvious is that the RR cut was a natural rally point. The lane to the rear led directly into the ammunition reserve. It was also an interior line of communication.
Under the lash of Bragg's orders, General Polk mounted attack after attack against Hazen's Brigade over a two hour period of time.
There is no way to exaggerate the intensity of the fighting in this confined battle space. The regiments in the front line exhausted both ammunition supplies & men. Under fire they were replaced by regiments by a passage of the line under fire from the relative safety of the RR cut.
The men relieved from the first line lay down while ammunition & water was distributed. They were not alone.
The lines of attackers drove a wave rabbits before them. The terrified creatures bounded into the RR cut & snuggled for cover under the men.
Having rehydrated, washed out the fouling & refilled their cartridge boxes, the regiment was ready to return to the first line in a passage of the line under fire.
Because the defenders were able to maintain a constant effective fire superiority over the attackers with passages of lines, the attackers suffered devastating casualties.
Unlike the Romans, General Polk failed to amass a striking force that could have overwhelmed Hazen's Brigade.
Instead of a passage of lines bringing forward fresh regiments to the firing line, Polk's men literally clamored over acres of bodies crowding the ground. It was possible to walk 1/2 a mile without touching the ground.
In contrast, Hazen's regiments had suffered remarkably light casualties. Had they not displayed tactical competence with their successful passage of lines under fire, quite another narrative of the Battle of Stones River would have been written.
Note: I found a very educational source on the topic of passage of lines.
This paper cites historic sources & modern conflicts to discuss the passage of lines under fire. Read more here.
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