Part of the elaborate Confederate works outside Petersburg, after their evacuation in April 1865; such trenches extended for many miles in both directions.
Following a series of engagements a state of mutual siege arose when the Army of the Potomac encountered the Army of North Virginia in the region of a crossroads known as Cold Harbor. Once again, the Union troops entrenched immediately they discovered the Confederate trenches. And once again, attacks on Confederate trenches were all frontal assaults, executed in waves. A major Union assault was launched on 3 June. Wherever Union troops faltered as they were hit by Confederate fire, they dug in. When some Federal troops crossed no-man’s-land, broke through the defensive palisades, mounted the parapet of the Confederate trenches and jumped in to engage in hand-to-hand fighting, all semblance of order was completely lost. Some managed to break into the Confederate positions and advance towards the enemy rear. Yet again, a timely counter-attack pushed them back. In other places, close-range fire destroyed the massed ranks of the attacking Union troops. Rather than either side making any kind of progress, however, stalemate began to develop. The casualties were even higher than during the attack on the Mule Shoe: some 3,500 Federals in one hour of fighting. It was a deeply traumatic defeat, the cause of which was poor planning as well as Grant’s persistence with engaging the Army of North Virginia in a series of head-on assaults.
The significant difference in this battle, however, was that the Union troops dug in where they were stopped, rather than falling back to their original positions. Because this was done by a large number of troops, a new line of trenches, closer to the enemy line, was dug. In many places, the depth of no-man’s-land was now no more then 40 yards. The new Federal line was soon as strong as their start line had been and as strong as the Confederate trenches in front of them. Although it had never been Grant’s intention that his troops should lay siege to the Confederates, that is what happened for the better part of ten days. Part of the reason for this eventually was Grant’s decision to transfer his focus of operations to Petersburg. For several days during the first week of June, both the Confederates and the Federals reinforced their trenches and, in some places, dug rifle pits in front of their main positions, which were then extended to form trenches, but the Federals were especially assiduous. Networks grew on each side as communication trenches were dug, redoubts were built and bomb-proof dugouts were added. Some trenches zigzagged to avoid being enfiladed, while some communication trenches were covered to conceal movement forward to the front line. Gun emplacements were also constructed and tunnels were dug out to piquet posts so that troops could move to and from them safely. The secondary lines in the trench networks were essential because of the range of rifle bullets. Anyone throughout the entire depth of the defensive area was vulnerable to hostile fire, so it was essential that trenches were dug behind the front line. Some were no more than shelter pits and short trenches, unconnected by communication trenches to the main entrenchments. Some trenches were deep enough for a man to stand upright without exposing his head, while others were no more than shallow scrapes. This became, for a short time, mutual siege and, hence, the embodiment of trench warfare. Meanwhile, artillery, mortar and rifle fire was exchanged sporadically throughout the construction process. Snipers or sharpshooters positioned themselves at loopholes and picked off the enemy as he exposed himself working, crossing poorly constructed earthworks or out in the open, including at night when the moon shone. Their activities never ceased, partly because they were never short of targets and partly because the lines were so close; 125 yards or even 40 yards were not uncommon.
Part of the process was to engage in conventional siege operations and it was with this is mind that the Federals began digging towards the Confederate lines and constructing parallels. The purpose of this was to get the troops closer to the enemy before launching an assault. Most of this work was done on the southern flank of the line, but it was carried out all along the Federal line. While the men dug, the Confederates fired on them, day and night. In a significant deviation from conventional practice, much of the digging of saps towards the Confederates was done without the use of a sap roller which, once detected, rather gave the game away, because the Federals were so close to the Confederate positions. Instead, men went over the parapet in the dark and dug without the protection of the roller, towards the enemy, back to the Federal line and outwards to form a parallel. Although this was not in itself novel, since the method was clearly set out in the manuals, it was unusual and set a precedent that was to be repeated on future battlefields elsewhere.
During the night of 5 June, a detachment of the US Engineer Battalion, aided by infantrymen, began the preliminary work on a mine under the Confederate line. The following night, they started excavating the gallery. But the mine was never finished. After several days, and before the entrenching and mining were finished, Grant ordered all siege work to stop. The focus of attack was now to be Petersburg. For the next five days, both Confederate and Union troops remained in their lines and the dead remained where they had fallen. In the summer heat, the bodies rapidly decomposed and the smell soon became overwhelming. On 7 June, a truce was agreed whereby the dead in no-man’s-land could be buried without hindrance from either side.
It is clear that the idea to start siege operations was not well considered as the area in which the two armies were entrenched was bounded by rivers which allowed little room for manoeuvre. Crossing the River Chicahominy to the south would be self-defeating and gain Grant nothing. Worse than this, however, was the nature of the ground over which the siege works were being advanced. The Confederates held the higher ground so could look down into the Federal positions and, indeed, fire into them; the Federals had the disadvantage of having to fight uphill. A similar problem, but on a much larger scale, was to beset the British and French in the First World War.
While it would be stretching a point to claim that the ten-day period of trench warfare at Cold Harbor was unique to Civil War battlefields, nevertheless, it is true to say that the men on both sides lived, ate, worked and slept in the trenches. The officers had it slightly better than their men as most had access to tiny shelters, or dugouts, out of the front line. This period of stalemate was a significant development in trench warfare, one which was noticed at the time, drawing direct comparisons with other battles, and especially with sieges. However, there was no sense that mutual siege of this sort was a foretaste of the future. Just one week of mutual siege highlighted the practical difficulties of supplying entrenched troops with essentials such as water, food and ammunition. Water was a particular problem because without it life was unsustainable, let alone military operations. Indeed, no satisfactory solution to supplying it in large quantities was found and some men were forced to dig down to find wet clay from which some wetness could be forced. Salvation came in the form of a night-time rain storm which flooded the trenches, thereby highlighting another problem, that of draining water away. At dawn, the stand-to was normal routine and units were rotated from the front line to the support line every 24 hours, a matter of necessity to allow men to rest for 48 hours, although sometimes lack of manpower did not allow rotations and men had to stay in the line until the operations at Cold Harbor ended.
The conditions were not good. Most of the narrow trenches were cramped and overcrowded making sleep next to impossible. There were no proper latrines and the men had no opportunity to wash because of the lack of water. It is not surprising that such conditions encouraged lice, while the unburied dead, who lay all around, attracted rats. Men became ill with typhoid and dysentery due to the unsanitary conditions. All were under constant stress as there was little respite from the firing or the bad conditions, while only the bomb-proof shelters offered any degree of safety. A spontaneous phenomenon that was to be repeated many times during the First World War occurred, despite the short duration of the mutual siege: the brief live-and-let-live truce. Not only did some men on both sides suddenly stop shooting, but they effectively stopped warring to the extent that others could enter no-man’s-land or expose themselves above the parapet without attracting hostile fire; ordinarily, such bravado would be fatal. One reason, no doubt, for these spontaneous acts was stress. Nevertheless, the morale on both sides remained high, although the Federals were less buoyant due to their failure to take the Confederate positions and because of their consequently high casualties. There was inevitably a higher loss among officers and NCOs because they led from the front.