The tactic that Union forces used to defend Little Round Top was defensive formations.

As Confederate troops moved forward on July 2, 1863, Union forces, especially the 20th Maine led by Colonel Joshua Chamberlain, established robust defensive positions. They took advantage of the terrain, creating a line that allowed them to successfully fend off numerous attacks. Confronted with daunting odds, Chamberlain commanded a bold bayonet charge, which reinforced their defensive approach. This blend of formations and tactical maneuvers played a vital role in securing Little Round Top and contributing to the Union's overall victory at Gettysburg.