The main reason for the Union Army’s success on the second day of the Battle of Gettysburg was the effective use of terrain.

The Union forces strategically seized elevated positions like Little Round Top and Cemetery Ridge, which offered considerable defensive benefits. This enabled them to leverage the natural landscape to successfully fend off numerous Confederate assaults. The terrain not only bolstered their defense but also improved the effectiveness of their artillery, playing a crucial role in their ability to maintain key positions against persistent Confederate attacks throughout the day.