As Confederate Major General John Bell Hood's Texans relentlessly battered the gritty defenders of the Southern Ridge of Little Round Top, the men in blue began to give way. Determination alone could not hold this ground. Upon Colonel Vincent's mortal wounding, Colonel Rice of the 44th New York would take command of this lone brigade, leading the fight to defend the ridge. Of this struggle, he would later write, "Massing two or three brigades of his (Hood's) force, he tried for an hour in vain to break the lines of the Forty-fourth New York and Eighty-third Pennsylvania, charging again and again within a few yards of these unflinching troops. At every charge he was repulsed with terrible slaughter. Despairing of success at this point, he made a desperate attack upon the extreme right of the brigade, forcing back a part of the Sixteenth Michigan." [5] The 4th and 5th Texas had found a crack in the Union line. Exploit this, and the Butternuts could sweep the Federals from the hill.

Major General Gouverneur K. Warren, whose earlier messenger directed Colonel Vincent's Brigade to the unprotected hill, knew that these men needed support to stem the irresistible, onrushing tide of gray. Finding more troops nearby, General Warren again asked for help. Like Vincent before him, Colonel Patrick O'Rorke, who had previously served under Warren, took upon his shoulders the responsibility of moving his men without orders to where the need was greatest. Of this pivotal portion of the struggle, Colonel Rice would offer, "This regiment (the 16th Michigan) was broken,...but being immediately supported by the One hundred and fortieth New York Volunteers, the line became again firm and unbroken." Colonel Garrard of the 146th New York, a sister regiment to the 140th, would add to the Rice's laconic description. "The One hundred and fortieth was formed in line, and was immediately closely engaged with the enemy at short musket-range on the left slope of the ridge...Colonel O'Rorke was mortally wounded at the head of his regiment while leading it into action." Again, like Vincent, O'Rorke would sacrifice himself to save this vital position on the far left of the Union line. Twenty-seven year old Patrick O'Rorke, newly married and first in his class at West Point, lay dead on the field as his men dutifully fought on.

As the Union soldiers struggled to acquire the reinforcements they would need to hold Little Round Top, the Confederates of Major General John Bell Hood's Division of General Longstreet's Corps charged again and again threatening to take this anchor of the Federal line. Commanding the Texas Brigade, Confederate Brigadier General Jerome Bonaparte Robertson described the mayhem.

"At this point, my assistant adjutant and inspector general reported from the Fourth and Fifth that they were hotly engaged, and wanted re-enforcements. My courier, sent to General Hood, returned, and reported him wounded and carried from the field. I sent a messenger to Lieutenant-General Longstreet for re-enforcements, and at the same time sent to General [George T.] Anderson and Benning, urging them to hurry up to my support. They came up, joined us, and fought gallantly;, but as fast as we would break one line of the enemy, another fresh one would present itself, the enemy re-enforcing his lines in our front his reserves at the base of the mountain to our right and front, and from his lines to our left. Having no attack from us in his front, he threw his forces from there on us."

But despite their determined efforts, the Southerners would finally back away, unable to take this crucial high ground on the far left of the Union line. Their day was not without success however as they still held portions of Houck's Ridge and the Devil's Den. Of his brave Texans, General Robertson would later speak with pride and sadness. "The Fourth and Fifth Texas, under the command of Majors J. P. Bane and J. C. Rogers, continued to hold the ground of their original line, leaving the space over which they had made their successive charges strewn with their wounded and dead comrades, many of whom could not be removed, and were left upon the field...In this, the hardest fought battle of the war in which I have been engaged, all, both officers and men, as far as my observation extended, fully sustained the high character they have heretofore made." [5]