John Reynolds’ I Corps led the Union Army’s march to Gettysburg on July 1, and Brig. Gen. Lysander Cutler’s brigade led the I Corps. As they approached the Codori house along the Emmitsburg Road, the men left the road and angled northwest, cutting across fields and knocking down fences as they tramped. Artillery fire from Lt. John H. Calef’s Battery A, 2nd U.S. Artillery, was clearly audible and served to quicken their pace. The first two regiments in the brigade’s column, the 76th New York and 56th Pennsylvania, crossed Chambersburg Pike. In its haste to relieve sections of Calef’s battery north of the road, Captain James Hall’s six-gun 2nd Maine battery made a sudden dash between the 56th Pennsylvania and the next regiment in line, the 147th New York. The result was that the latter regiment remained on the south side of Chambersburg Pike with the 84th and 95th New York near the McPherson farm buildings. Hall’s battery finally dropped trail between Chambersburg Pike and the unfinished railroad while Calef’s guns withdrew to the Lutheran Theological Seminary, where the men rested and restocked their ammunition. As Cutler’s men took up their new positions, Maj. William Pegram’s Confederate artillery battalion on Herr Ridge hurled shells in their direction. Casualties appeared almost immediately.6
As the six hundred Federal infantry of the 76th New York and 56th Pennsylvania continued moving north from the unfinished railroad cut, 1,700 men in the 2nd Mississippi, 42nd Mississippi, and 55th North Carolina of Brig. Gen. Joseph Davis’ Brigade rapidly approached from the west. These were large regiments, each numbering more than 500 men, but only the 2nd Mississippi had significant combat experience. The three regiments were part of Heth’s Division of A. P. Hill’s Third Corps, and had marched behind Brig. Gen. James Archer’s Brigade on Chambersburg Pike as they approached Gettysburg. Archer deployed on the right (south) of the road, while Davis formed his regiments into line of battle on Archer’s left. Davis’ entire sizable command numbered 2,300 muskets, but the 11th Mississippi was in the rear guarding the trains. At about 10:30 a.m., with the veteran 2nd Mississippi in the middle of the line and the two inexperienced regiments deployed on either side—the 55th North Carolina on the left flank and the 42nd Mississippi on the right—the brigade advanced about one mile preceded by a skirmish line. The 55th North Carolina began curving its march to the northeast as it passed the Bender farm.7
Davis’ men suddenly materialized in the wheat fields in front of the 76th New York and 56th Pennsylvania as the Federal troops reached their positions north of the unfinished railroad cut. General Cutler reported that the enemy was “advancing in two lines, at short range, in front and on my right flank." Although second in line, the 56th Pennsylvania completed its deployment from column into line of battle before the 76th New York to its right. Seeing troops in front of him, Col. William Hofmann of the 56th Pennsylvania asked General Cutler, “Is that the enemy?" Cutler, who had been watching the movements through his binoculars, answered in the affirmative. Hofmann yelled to his men, “Ready, Right Oblique! Aim! Fire!" The rounds struck two members of the 55th North Carolina’s color guard—the first recorded shots fired by Federal soldiers during the battle.
The 2nd Mississippi and 55th North Carolina quickly responded. The men leveled their weapons and fired, killing and wounding an unrecorded number of Pennsylvanians. Still moving into position, the 76th New York received a raking fire and several men fell. Unable to see any enemy soldiers, its commanding officer, Maj. Andrew Grover, assumed the fire was coming from Federal troops and ordered his New Yorkers to hold their fire. Another volley ripped through his line. Grover, still unconvinced of the source, continued cautioning his men to hold their fire. When he finally spotted the 2nd Mississippi rising out of the fields in front of him, the major ordered his embattled men to defend themselves.8