Throughout much of the morning, the battle along the line had turned into a vast, bloody standoff. As Confederate General Robert E. Lee fed more and more Confederate units into the fray as the battle developed and Confederate units arrived on the field, a Union force that could barely stand against the Army of Northern Virginia when the Northerners outnumbered the Southerners three to one, suddenly found they were slowly becoming the minority of troops on the field.

The strain reached a climax around 3:30 p.m. when Confederate General Jubal Early's Division formed up on Mummasburg Road virtually undetected to within striking distance of the Union right flank. The right flank of the Union forces was comprised of the Eleventh Corp.

The Eleventh Corp stretched from Mummasburg Road, where it fronted on Dole's Confederate Brigade, to Harrisburg Road, where the right wing was hoping to move foward in such a way as to catch Dole's troops in the flank.

Military historians have speculated that Dole boldly approached the Eleventh Corp for the singular purpose of baiting them into attempting to get on his left flank. Dole was aware that Early was coming up on the Harrisburg Road, and baiting the over-confident Union troops to attack could set them up to become a victim of their own device...that is, the intended flankers could readily find themselves flanked when Early came up.

The main assault on the right flank of the Union line, Barlow's division, was spearheaded by Confederates from Early's Division under General John B. Gordon (who some say may have well evolved into the next "Stonewall" Jackson, had Early and others given this aspiring general more latitude).

Gordon's Georgians struck the Union line with that irresistible fury the brigade had become known for. The Georgia Brigade actually formed the right of Early's battleline, and they would strike Barlow's line on Ames' Brigade of Barlow's Division.

Ames' Brigade had advanced nearly as far as Rock Creek, which lies perhaps a few hundred feet below the knoll, where they had placed themselves as the division advanced and pivoted to strike Dole on his flank.

The Georgia Brigade charged across Rock Creek and smashed into Ames, sending his brigade retreating expeditiously back up on Barlow's Knoll (aka the "Almshouse Line"). The Union line rallied here and stood ready to receive Gordon's further advance, but Gordon's attack was not the only surprise in store. As the Union troops took aim at the rapidly advancing Georgians, they were suddenly struck on the right by Early's brigades under Hays and Avery.

The Union right was being quickly enveloped and reinforcements sent in by the Union command in the form of Coster's Brigade and Devin's Cavalry could not stop it. The Eleventh Corps was quickly reduced to a panicked withdrawal.

The entire Union line was thus placed in peril, and there was nothing left to do but retreat in haste. The Confederates were going to quickly domino the whole Union line from the right if the Union forces did not fall back.

An attempt was made by the First Corps to fall back to and take a stand on Seminary Ridge, but it was a doomed effort as more and more Confederate units were freed-up to assault the First Corps position as a result of the general collapse of the Union line. Suddenly, virtually the entire Union line then on the field retreated in disorder through town and toward Culp's Hill and Cemetery Ridge. The "great skeedaddle" essentially marked the end of the first day.

Of the more than 16,500 Union troops that had formed the Union line on the first day, only 5,500 made it to Culp's Hill and Cemetery Ridge. Nearly 6,500 Union soldiers lie dead or wounded on the field between Marsh Creek and Seminary Ridge and Rock Creek and into the streets of the town. Almost 5,000 had been captured.