The plan of forming a breach in the Southern works, by exploding a mine beneath them, is said by Northern writers to have originated with a subordinate officer of the Federal army, who, observing the close proximity of the opposing works near Petersburg, conceived it feasible to construct a subterranean gallery, reaching beneath those of General Lee.  The undertaking was begun, the earth being carried off in cracker-boxes; and such was the steady persistence of the workmen that a gallery five hundred feet long, with lateral openings beneath the Confederate works, was soon finished; and in these lateral recesses was placed a large amount of powder.

All was now ready, and the question was how to utilize the explosion.  General Grant decided to follow it by a sudden charge through the breach, seize a crest in rear, and thus interpose a force directly in the centre of Lee’s line.  A singular discussion, however, arose, and caused some embarrassment.  Should the assaulting column consist of white or negro troops?  This question was decided, General Grant afterward declared, by “pulling straws or tossing coppers”—­the white troops were the fortunate or unfortunate ones—­and on the morning of July 30th the mine was exploded.  The effect was frightful, and the incident will long be remembered by those present and escaping unharmed.  The small Southern force and artillery immediately above the mine were hurled into the air.  An opening, one hundred and fifty feet long, sixty feet wide, and thirty feet deep, suddenly appeared, where a moment before had extended the Confederate earthworks; and the Federal division, selected for the charge, rushed forward to pierce the opening.

The result did not justify the sanguine expectations which seem to have been excited in the breasts of the Federal officers.  A Southern writer thus describes what ensued: 

“The ‘white division’ charged, reached the crater, stumbled over the debris, were suddenly met by a merciless fire of artillery, enfilading them right and left, and of infantry fusillading them in front; faltered, hesitated, were badly led, lost heart, gave up the plan of seizing the crest in rear, huddled into the crater, man on top of man, company mingled with company; and upon this disordered, unstrung, quivering mass of human beings, white and black—­for the black troops had followed—­was poured a hurricane of shot, shell, canister, musketry, which made the hideous crater a slaughter-pen, horrible and frightful beyond the power of words.  All order was lost; all idea of charging the crest abandoned.  Lee’s infantry was seen concentrating for the carnival of death; his artillery was massing to destroy the remnants of the charging divisions; those who deserted the crater, to scramble over the debris and run back, were shot down; then all that was left to the shuddering mass of blacks and whites in the pit was to shrink lower, evade the horrible mitraille, and wait for a charge of their friends to rescue them or surrender.”