The Confederates had found a natural defensive position, a narrow road used by farm wagons which had become sunken due to wear from wagon wheels and erosion caused by rain. This obscure sunken road would become famous as "Bloody Lane" by the end of the day.
Approaching five brigades of Confederates positioned in this natural trench, Union troops marched into a withering fire. Observers said the troops advanced across open fields "as if on parade." The shooting from the sunken road stopped the advance, but more Union troops came up behind those who had fallen.
The Irish Brigade Attacked the Confederates at the Sunken Road
Eventually the Union attack succeeded following a gallant charge by the famed Irish Brigade, regiments of Irish immigrants from New York and Massachusetts. Advancing under a green flag with a golden harp on it, the Irish fought their way to the sunken road and unleashed a furious volley of fire at the Confederate defenders.
The sunken road, now filled with Confederate corpses, was finally overtaken by Union troops. One soldier, shocked at the carnage, said the bodies in the sunken road were so thick that a man could have walked on them as far as he could see without touching the ground.
With elements of the Union Army advancing past the sunken road, the center of the Confederate line had been breached and Lee's entire army was now in peril. But Lee reacted quickly, sending reserves into the line, and the Union attack was halted in that part of the field.
To the south, another Union attack began.