Iverson's gravest error
thus the fence was closer to the west of the hill at this point than it was farther to the left, where the 97th New York was posted. . While the left of the brigade was being realigned, the 12th Massachusetts shifted its line to the left to face Iverson. It formed along the same rock fence occupied by the rest of the brigade to the left, except here the fence was offset to the west some 20 yards. The movement of the 12th Massachusetts permitted the 90th Pennsylvania, which now formed the right of the brigade line, to slide to its left. The left wing of the 90th formed facing westward, while its right wing formed along the Mummasburg Road, facing north.
During this movement the 90th Pennsylvania found itself exposed to a heavy fire from O'Neal's skirmishers to the north, and the 12th Massachusetts encountered fire from another advancing enemy line, perhaps the 3rd Alabama. Robinson could not afford to leave his right unsupported, so he called forward Paul's brigade from its reserve position in front of the Seminary. Doubleday was able to spare Paul's men because there was not at the moment any other Confederate pressure along his line. Doubleday directed Robinson to accompany Paul's advance in person.
Paul's command, however, would not arrive in time to meet the height of Iverson's attack. Baxter's men reformed their line facing Iverson very carefully so they would not be seen by the enemy. As already noted, the left part of the line was hidden from Iverson's view by the crest of the ridge, while the right portion lay behind a stone wall. V. E. Turner of the 12th North Carolina remarked that Iverson's men were "not knowing certainly where the enemy was, for his whole line, with every flag, was concealed behind the rock wall on their right and the drop in the ground on their left. Not one of them was to be seen."