Upvote:2
The actual answer is that Pettigrew's troops on the third day achieved the high water mark. The stone wall that formed the federal line had a zig zag and was closer to the front where Pickett struck the wall. His men crossed the wall, but not far, only a few feet to capture the battery there.
To Pickett's left, further north, the wall moved directly east 80 yards (known as the Angle) then turned north again. Pettigrew's troops reached that wall, but did not cross it, but undoubtedly got farther than any of Pickett's men did except as prisoners.
Wright's claim to have reached the crest is a lot less convincing, and is usually considered post-war "coulda shoulda woulda" thinking. The counterattacking forces of Stannard were coming from the North, more or less down the ridgeline and moved forward to attack. There were also 6th corps units from the front that would have been between him and any rosy vision of the Baltimore Pike, which was about a mile off and invisible in the darkness that was descending on the field at the time - it was well past sunset.
It is far more likely Wright mistook one of the many interim positions taken by delaying forces after the 3rd corps was shattered for the military crest of Cemetery Hill.