  At several places east of the city the opposing lines were extremely close together. One of these locations was in front of Pegram’s (sometimes called Elliott’s) Salient, a Confederate strong point near old Blandford Church. Here the Confederate position on Cemetery Hill and the Union picket line were less than 400 feet apart. Because of the proximity of the Union line, Pegram’s Salient was well fortified. Behind earthen embankments was a battery of four guns, and two veteran South Carolina infantry regiments were stationed on either side. Behind these were other defensive works; before them the ground sloped gently downward toward the Union advance line. This forward Union line was built on the crest of a ravine which had been crossed on June 18. Through this ravine, and between the sentry line and the main line, lay the roadbed of the Norfolk and Petersburg Railroad. The front in this sector was manned by Maj. Gen. Ambrose E. Burnside’s IX Corps. Among the many units which composed this corps was the 48th Regiment, Pennsylvania Veteran Volunteer Infantry. A large proportion of this regiment was made up of onetime coal miners, and it apparently occurred to one or more of them that Pegram’s Salient would provide an excellent place to use their civilian knowhow. Lt. Col. Henry Pleasants, the commanding officer of the 48th and a mining engineer by profession, overheard one of the enlisted men mutter, “We could blow that damned fort out of existence if we could run a mine shaft under it.” From this and similar remarks came the germ of the idea for a Union mine. The 48th Regiment proposed to dig a long gallery from the bottom of the ravine behind their picket line to a point beneath the Confederate battery at Pegram’s Salient, blow up the position by powder placed in the end of the tunnel, and then send a strong body of troops through the gap created in the enemy’s line by the explosion. They saw as the reward for their effort the capitulation of Petersburg and, perhaps, the end of the war. After obtaining the permission of Burnside and Grant, Pleasants and his men commenced digging their mine shaft on June 25. The lack of proper equipment made it necessary to improvise tools and apparatus with which Lt. Col. Henry Pleasants, onetime mining engineer and the commanding officer of the 48th Pennsylvania Regiment which dug the tunnel under the Confederate line. Cross-section view of the Federal tunnel under the Confederate line. Colonel Pleasants later recalled that “General Burnside told me that General Meade and Major Duane, chief engineer of the Army of the Potomac, said the thing could not be done—that it was all clap-trap and nonsense; that such a length of mine had never been excavated in military operations, and could not be; that I would either get the men smothered, for want of air, or crushed by the falling of the earth; or the enemy would find it out and it would amount to nothing.”
One of the most remarkable features of the gallery was the method devised to supply the diggers at the end with fresh air. The longer the tunnel grew, the more serious the problem of ventilation became. It had been considered impossible to dig a tunnel for any considerable distance without spacing shafts at regular intervals in order to replace the polluted air with a fresh supply. This problem had been solved by the application of the simple physical principle that warm air rises. Behind the Union picket line and to the right of the mine gallery, although connected with it, the miners dug a ventilating chimney. Between the chimney and the mine entrance they erected an airtight canvas door. Through that door and along the floor of the gallery they laid a square wooden pipe. A fire was then built at the bottom of the ventilating shaft. As the fire warmed the air it went up the chimney. The draft thus created drew the bad air from the end of the tunnel where the men were digging. As this went out, fresh air was drawn in through the wooden pipe to replace it. Work on the tunnel continued steadily from June 25, and by July 17 the diggers were nearly 511 feet from the entrance and directly beneath the battery in Pegram’s Salient. The Confederates had learned of the mine by this time and had dug several countermines behind their own lines in an effort to locate the Union gallery. Two were very close, being dug on either side of where the Pennsylvanians were at work. Although digging in the countermines continued throughout July, Confederate fears seemed to lessen during the same period. There were many reasons for this, one being the failure of their tunnels to strike any Union construction. Another major reason, undoubtedly, was a belief held by many that it was impossible to ventilate a shaft of any length over 400 feet without constructing air shafts along it, and so far no air shafts could be seen between the Union and Confederate lines. The next step in the Union plan was to burrow out into lateral galleries at the end of the long shaft. Accordingly, on July 18, work was begun on these branches which extended to the right and left, paralleling the Confederate fortifications above. When completed, these added another 75 feet to the total length of the tunnel which now reached 586 feet into the earth. It was about 20 feet from the floor of the tunnel to the enemy works above. The average internal dimensions of the shaft were 5 feet high, with a base 4½ feet wide tapering to 2 feet at the top. Digging was finally completed on July 23. Four days later the task of charging the mine with black powder was accomplished. Three hundred and twenty kegs of powder weighing about 25 pounds each were arranged in the two lateral galleries in eight magazines. The total charge was 8,000 pounds. The powder was sandbagged to direct the force of the explosion upward and the fuses were spliced together to form a 98-foot line. Meanwhile, preparations for the large-scale attack which was to follow the explosion of the mine had been carried out. Burnside wanted his IX Corps to lead the attack, spearheaded by a fresh, 4,300-man Negro division, and pressed his wishes on Meade. Both Meade and Grant approved the request, but refused to allow the black troops to lead the assault for fear that, if the attack failed, the Union commanders could be accused of wanting to get rid of the only Negro troops then with the Army of the Potomac. Burnside did not learn of this decision until the day before the assault, July 29, and he was forced to change his plans at the last moment. Three white divisions would make the initial charge, with the black division in reserve. Burnside had the commanding generals of these three divisions draw straws to see which would lead. Brig. Gen. James F. Ledlie of the 1st Division won the draw. Despite these 11th-hour changes, a plan of battle had been evolved. During the night of July 29-30, the bulk of the IX Corps was assembled in the ravine behind the mine entrance and in the two approach trenches leading to the picket line. Troops from other Union corps were marshalled as reinforcements. Artillerymen, manning 110 guns and 54 mortars, were alerted to begin shelling the Confederate line. To assist the attack, Grant sent a cavalry and infantry force north of the James to threaten the Richmond defenses and destroy whatever they could of the Virginia Central Railroad. The object was to draw as many of Lee’s soldiers away from Petersburg as possible. And it worked. When the assault came, only 18,000 Confederates were left to guard the city. At 3:15 a.m., July 30, Pleasants lit the powder fuse and mounted the parapet to see the results of his regiment’s The awesome spectacle of the mine explosion caused a delay in the Union charge following the explosion. Removal of obstructions between the lines caused further delay. Soon, however, an advance was made to the crater, where many of the attacking force paused to seek shelter on its steep slopes or to look at the havoc caused by the mine. The hard-pressed Confederates rallied quickly and soon were pouring shells and miniÉ balls into their opponents. Union reinforcements poured into the breach; but, instead of going forward, they either joined their comrades in the crater or branched out to the immediate right and left along the lines. By 8:30 that morning a large part of the IX Corps had been poured into the captured enemy salient. More than 15,000 troops now milled in and about the crater. By prompt action and determined effort the Confederates had prevented a breakthrough. The attention of three batteries was soon directed on the bluecoats at the crater. Artillery hammered with shot and shell the huddled groups of increasingly demoralized men. In addition, mortars brought to within 50 yards of the crater dropped shells on the soldiers with deadly effect. Successful as these devices were in halting the Union advance, Lee was aware that an infantry charge would be necessary to dislodge the enemy. By 6 a.m. an order had gone out to Brig. Gen. William Mahone to move two brigades of his division from the lines south of Petersburg Colonel Pleasants’ sketch of the Crater.
In spite of the Confederate resistance, part of the Northern black division and other regiments had, by 8 a.m., advanced a short distance beyond their companions at the crater. Shortly thereafter, Mahone’s lead Confederate brigade arrived on the scene. The men filed into a ravine about 200 yards northwest of the crater and between it and Petersburg. No sooner had they entered this protected position than, perceiving the danger to their lines, they charged across the open field into the mass of Federal soldiers. Although outnumbered, they To many soldiers, the explosion of the mine and the bitter Battle of the Crater that followed were the most memorable events of the siege. Artist A. R. Waud sketched the explosion from the Union lines. By 10:30 another of Mahone’s brigades had reached the point of danger, and it charged the Union troops holding the crater, only to be repulsed. Meanwhile, the lot of the Northern soldiers was rapidly becoming unbearable. Confederate artillery continued to beat upon them. The closely packed troops (dead, dying, and living indiscriminately mixed) lacked shade from the blazing sun, food, water and, above all, competent leadership. Meade had ordered their withdrawal more than an hour before the second Confederate charge, but Burnside delayed the transmission of the order till after midday. Many men had chosen to run the gantlet of fire back to their own lines, but others remained clinging to the protective sides of the crater. The last scene in the battle occurred shortly after 1 p.m. Soon it was all over. The Union army had lost more than 4,000 men killed, wounded, or captured, as against about 1,500 for the Confederates. Again, as on June 15-18, a frontal assault had failed to take the Confederate stronghold, even though Union numerical strength greatly exceeded that of the Confederates. At the battle’s close Grant had more than 83,000 men south of the Appomattox River; Lee had about 22,000. What 8,000 pounds of powder could do—the crater as it appeared in 1865. The Union soldier seated at the end of the tunnel gives an idea of the crater’s size. |
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