Before the battle, Confederate artillerists used a lone tree on this ridge to establish a killing range against any Federal attack. As Gen. George G. Meade's men surged past the tree, Confederates caught Union troops in a deadly crossfire. Gen. John Gibbon's division remained in the field behind this position as Meade attacked. A 60-degree day thawed the ground, and men wallowed in a sea of mud. Gibbon sent forward skirmishers, who exchanged fire with their Confederate counterparts as cannonading and skirmishing grew nearer and more vigorous.