Little Round Top is an Avalon Hill game from 1979 for two players which recreates this critical battle.
During a typical game turn, both players move their company sized forces over a map of the battle area, positioning them for rifle fire and bayonet charges. Fire and melee combat are resolved by a die roll on the appropriate Combat Results Table. Regimental officers and their command abilities are crucial for keeping the attack moving forward or the defense intact.
It comes with a colorful map of the battlefield, 100 cardboard playing pieces, and a short rules booklet.