As Confederate General Evander Law's men strove to take the positions held by the men in blue on Houck's Ridge and the Devil's Den, a portion of his brigade detached and moved up and over Big Round Top. Lead by the determined Confederate Colonel William Calvin Oates, their orders were to attack and turn the far left of the Union line on Little Round Top. In their efforts to comply, they would encounter the hardy brave men of the 20th Maine Infantry Regiment who held these woods against charge after furious charge from Colonel Oates' 15th Alabama. Serving as defenders of the far left of the entire Union position, a line which started several miles away on Culp's and Cemetery Hills, Colonel Strong Vincent charged the 20th Maine with holding this ground on Little Round Top "at all hazards." To give up this ground meant risking the surging Confederates gaining this hill and threatening the rest of the long blue line. When the Southerners' repeated hammering frontal assaults failed to dislodge their determined counterparts, the Butternuts began sliding to their right in an attempt to get around or flank the end of the 20th Maine's line.

With many of his own men dead, wounded, or low on ammunition, and expecting another Confederate attack, Colonel Joshua L. Chamberlain gave the order to fix bayonets and charge. The surprised Southerners raced back to their former positions with many scooped up as prisoners along the way. Some reports suggest that the stalwart Confederate soldiers, exhausted, without water, and having marched 20 plus miles just to reach the battlefield, had already begun to pull back when the onrushing blue tide charged forward. Either way, the slaughter on this part of the field ended with the far left of the Union line secure. Possession of the rest of the fields further west however still hung in the balance.

Colonel Chamberlain later said, "The two lines met and broke and mingled in the shock. The crush of musketry gave way to cuts and thrusts, grapplings and wrestlings. The edge of conflict swayed to and fro, with wild whirlpools and eddies. At times I saw around me more of the enemy than of my own men; gaps opening, swallowing, closing again with sharp convulsive energy; squads of stalwart men who had cut their way through us, disappearing as if translated. All around, strange, mingled roar—shouts of defiance, rally, and desperation; and underneath, murmured entreaty and stifled moans; gasping prayers, snatches of Sabbath song, whispers of loved names; everywhere men torn and broken, staggering, creeping, quivering on the earth, and dead faces with strangely fixed eyes staring stark into the sky." [8]

Colonel William Calvin Oates, commander of the 15th Alabama and later Governor of Alabama, also wrote of the taxing trials of that singularly brutal day. In his memoirs, he would relive the gallantry and horror. "With a withering and deadly fire pouring in upon us from every direction, it seemed that the entire command was doomed to destruction. While one man was shot in the face, his right hand or left hand comrade was shot in the side or back. Some were struck simultaneously with two or three balls from different directions. Captains Hill and Park suggested that I should order a retreat; but this seemed impracticable. My dead and wounded were then greater in number than those still on duty. Of 644 men and 42 officers, I lost 343 men and 19 officers. The dead literally covered the ground. The blood stood in puddles on the rocks. The ground was soaked with the blood of as brave men as ever fell on the red field of battle." [2]

Colonel Oates wrote the above several decades after his regiments participation in the battle on July 2, 1863.  His after action report mentioned similar details but with dramatically different numbers. As he described the climax of the fight, Colonel Oates stated, "Finally, I discovered that the enemy had flanked me on the right, and two regiments were moving rapidly upon my rear and not 200 yards distant, when, to save my regiment from capture or destruction, I ordered a retreat.

Having become exhausted from fatigue and the excessive heat of the day, I turned the command of the regiment over to Captain B. A. Hill, and instructed him to take the men off the field, and reform the regiment and report to the brigade.

My loss was, as near as can now be ascertained, as follows, to wit: 17 killed upon the field, 54 wounded and brought off the field, and 90 missing, most of whom are either killed or wounded. Among the killed and wounded are 8 officers, most of whom were very gallant and efficient men. Recapitulation. -Killed, 17; wounded, 54; missing, 90; total, 161." [5]

Conspicuously absent in the latter (but earlier) recounting of these events are numbers that would account for the Alabamians captured by the 20th Maine during their final offensive. Colonel Oates specifically states that of the 90 missing, most were "either killed or wounded" suggesting that, in his view at least, those captured by the men from Maine were those wounded and left on the field. Colonel Rice, who assumed command of the Brigade after Colonel Vincent's wounding, mentioned the following in his official report. "The fearful loss of the enemy during this struggle may be estimated from the fact that over 50 of his dead were counted in front of the Twentieth Maine Regiment, and his loss was nearly in that proportion along our entire line." [5] If Colonel Oates' numbers were correct, over 30 of the 50 dead would have been from other regiments.

Colonel Rice would also mention in his report his orders following the successful defense of Little Round Top. He stated, "The enemy was now attempting to take possession of Round Top hill, a commanding position overlooking our left. It was evident no time was to be lost, and I sent at once other officers, whom I pressed into my service, with messages to the general commanding the corps, asking for re-enforcements to support the brigade. The messages were promptly delivered, and five regiments were at once sent to my support from the Third Division, General Crawford, under command of Colonel Fisher. Having, with the aid of this officer, properly disposed of three regiments of this force, I ordered Colonel Chamberlain, of the Twentieth Maine, to advance and take possession of the mountain. This order was promptly and gallantly executed by this brave and accomplished officer, who rapidly drove the enemy over the mountain, capturing many prisoners." [5]

Brigadier General James Barnes of the 5th Corps would add to this confusing collection of this conflict's casualty numbers in his report with information supplied by Colonel Chamberlain. "The enemy threw down their arms and surrendered in large numbers; the others fled rapidly from the contest; 368 prisoners, including 1 colonel, 1 lieutenant-colonel, and a dozen other officers of lesser rank were sent to the rear; 50 of their dead lay upon the field, and large numbers of their wounded" Of the 20th Maine, General Barnes would add, "...30 of this gallant regiment were killed, over 100 were wounded, but not one was taken a prisoner, and none were missing."

General Barnes continued, "It was now nearly dark. A portion of the enemy appeared to have occupied the summit of the rocky hill to the left. The men of this brave regiment, exhausted by their labors, had thrown themselves upon the ground, and many of them sunk at once in sleep. Colonel Rice, now in command of the brigade, directed Colonel Chamberlain to drive the enemy from this height. The order was at one given. Roused again to action, and advancing with fixed bayonets and without firing, lest the smallness of their numbers might be suspected, they rushed up the hill. Twenty-five more prisoners, including some staff officers, were added to the number previously taken, with a loss to the regiment of 1 officer mortally wounded and 1 man taken prisoner by the enemy." [5]

As the 20th Maine's more rarely seen monument on Big Round Top proudly states, "The 20th Maine Reg't, Colonel Joshua L. Chamberlain, captured and held this position on the evening of July 2^D, 1863, pursuing the enemy from its front on the line marked by its monument below. The Reg't lost in the battle 130 killed and wounded out of 358 engaged. This monument marks the extreme left of the Union Line during the battle of the 3^D day."