They had been arriving all night, and there were at least seventy thousand men, drawn up in a defensive position that has often been likened to a fishhook. The barb of the fishhook was on Culp’s Hill, at the southeast side of the town. From there, the fishhook made an extreme left-hand turn at Cemetery Hill and made a two-mile run through the range of hills, culminating at the two hills, Little Round Top and Big Round Top.

George Meade was clearly in charge, but the most experienced battlefield commander on the scene was Major-General Winfield Scott Hancock. The least experienced federal commander was Daniel Sickles (1819–1914), a former New York City congressman, who commanded the Third Corps. Sickles made one of the earliest, and potentially fatal, decisions of the day when he asked permission to move his corps from Seminary Ridge to another line, almost a mile to the east. Meade refused at first, but he did not make his order one hundred percent certain, and Sickles—like General Ewell the night before—made a decision on his own.