The men of that famed unit paused for a few brief seconds until they saw Colonel Kelly, their brigade commander, holding aloft the torn green flag of one of his regiments, the 116th Pennsylvania, waving it over his head.
"Ireland!" he screamed, and he started up the slope at a run, green flag fluttering over his head.
The decimated regiments of Erin leapt forward with wild battle cries, racing up the slope straight at the guns on the heights.
It was a race that would be decided in seconds. Rammers didn't bother to sponge, calling for the fixed round of canister and powder bag to be slammed straight into the muzzle. Gunners struggled to roll their pieces forward even as the rammers slapped their loads down to the muzzle, one gun going off prematurely, blowing the rammer, his staff, and the canister out over the Irishmen, gunners working the wheels crushed by the recoil.
Gunnery sergeants fumbled with friction primers, setting them in, hooking on lanyards, shouting for crews to jump clear.
Some of the Irishmen were actually up over the parapet, Kelly on top, waving the flag.
One gun, then seven more, fired in the next few seconds, some of the rounds discharging straight into the faces of men only a few feet away. There seemed to be a horrified pause for the briefest of moments as both sides were staggered by the carnage wrought
At nearly the same instant Kelly dropped, and some claimed that even as he fell, tumbling inside the parapet he clutched the colors to his breast
A wild hysteria seized the few men left of the brigade as they scrambled up onto the parapet screaming for their colonel, dropping as Confederate infantry waded in around the guns to repel the charge. The surge broke at the crest and fell back, leaving a carpet of blue and red and small swatches of green flag in the mud.
Most of the rest of the line did not advance, the first volley having driven them to ground, to halt yet again along that terrible, invisible line that seems to appear on a battlefront a line that not even the bravest will pass, knowing that to take but one more step forward is death.
Some were demoralized, clutching the ground; others, in shock, were cradling wounded, dying, and dead comrades. Most settled down to the grim task at hand. Raising rifles, taking aim up the slope, firing, grounding muskets, reloading and firing again.
In the coldest sense of military logic, this battered line was the shield, the soak off, having taken the first position and now stalling in front of the second. Their job was simply to absorb the blows, to die, to inflict some death upon those dug in until the second and third lines came up, still relatively unscathed, to push the attack closer in.
And so across the next ten minutes they gave everything they had, these volunteers turned professionals, the pride of the Army of die Potomac, the pride of the Republic. Thousands of acts of courage were committed, none to be recorded except in the memories of those who were there, the greatest courage of all simply to stand on the volley line, to fire, to reload, and all die time the litany chant in the background…
"Pour it in to them. Close on the colors, boys. Pour it into them!"
Two hundred yards to the rear, the next assault wave reached the south bank of the flood plain, their officers ordering a halt, letting the men catch their breath for a few minutes, to gulp down some water, while forward their comrades died.
Atop the crest the Confederate forces blazed away, some of the men, acknowledged sharpshooters, calling for others to load, to pass their guns up, making sure that every shot counted, though in the still air, now laced again by showers, the smoke quickly built to a hanging cloud of fog.
Men were falling in the trenches, though not near as many as down on the open slope. Rifle balls smacked into the loosely piled dirt, spraying the men; shots when they hit tended to strike arms raised while ramming or, far more deadly, in the chest or face.
A growing line of dead and wounded lay directly behind the trench, dragged out of the way so as to not be trampled under.
The Union artillery was again in full play, though aiming in most cases too high out of fear of striking their own battle line in the confusion. But enough shots were tearing in to do terrible damage, a shell bursting on the lip of the parapet of Williamson's South Carolina troops, sweeping away eight men by his side.
A large cauldron that had been used to boil enough coffee for a regiment was struck by a solid shot, flipping it end over end, scalding men nearby, crushing the life out of a man unfortunate enough to be caught in its path.
An ammunition wagon went galloping off, two of the mules with broken legs the driver dead, the two mules still intact dragging the wreckage in a blind panic.
A brief burst of rain swept along the slope, hard enough that as men tore cartridges open the powder got wet and their guns then misfired. The rain, at least for the moment, cut down the clouds of smoke, opening the visibility.
The forward line of the Union assault was staggering. Men no longer able to take the sweeping blasts, many, especially in front of the batteries, beginning to drop back. A few were running; most were giving ground slowly, angry, bitter that after having come so far, they could go no farther.
Drum rolls echoed along the base of the slope; bugles sounded. The second wave, which had waited, hugging the slope along the flood plain embankment or resting in the shallow trench, stood up.
There was no cheering. These men were grim. They had marched over and through the carnage already wrought, lying alongside dead and wounded comrades and enemies in the shallow trench. More than one had given what was left of his canteen to a gut-shot rebel begging for water or a blinded lieutenant asking for someone to wash the blood from his eyes so he could see again.
As they stood up, the first wave of broken troops coming down the slope passed through them. This was always the hardest moment for the following waves in an attack. All ahead looked to be nothing but chaos and disaster, ground covered with bodies and parts of bodies, men contorted and twisted into only the poses that those who had died violently could assume, soldiers, on the edge of panic, screaming that the battle was lost, visual evidence on all sides of the fate that might be waiting just one more step ahead.
Nevertheless, the regiments rose up, heads bowed, pushing up the slope. Behind them the third wave, which had been waiting, crouched along the banks of the stream, stood up and started forward as well. The broken troops fell back. Some slid into the Confederate trench at the base, of the slope, rallying around a trusted officer, or their flags, though up forward a thin line still held, the colors of several regiments now planted in the ground, marking the point of farthest advance, or lying on the ground, the entire color guard dead or wounded.
For the next two minutes, the charge going up the ridge could not slow to open fire; too many of their own men were still in front Twenty-seven regiments stormed up the slope, men from New Jersey, two entire brigades from New York, and another from Pennsylvania, regiments from Ohio and Indiana, a lone regiment from the mountains of West Virginia, and another from the flat coastal plains of Delaware.
The lash of the hurricane descended on them. Gone was the panicked firing of the Confederate batteries about to be overrun by Kelly's now-annihilated brigade. Gunners took a few extra seconds, sighting their weapons as barrels were swabbed out and canister charges set in.
At two hundred yards, one entire battalion of guns cut loose with a salvo.
The impact dropped the entire line across a front of nearly a hundred yards, sweeping it to the ground like toy soldiers cast down by an angry child. At that point of the mile-wide advance the charge did not simply stop, it just disappeared into the ground.