The Northerners held, then lost, then retook the Thomas house grounds as the fighting ebbed and flowed in the stifling heat. Casualties mounted quickly on both sides. Union Maj. Gen. Lew Wallace could see that his numbers were dwindling and that the Confederates were coming in waves. Wallace gave the order to retreat. Under a raking of fire of both musketry and artillery, his troops pulled back and fled to the northeast past Gambrill Mill to the road to Baltimore. The Confederates won the battle, but the Union won a critical one-day delay in Lt. Gen. Jubal A. Early's attempted raid on Washington. Estimates vary greatly for troops and casualties in the Battle of Monocacy. The Union had approximately 5,800 men and suffered 1,294 killed, wounded, or missing. The Confederates had 15,000 to 16,000 troops and 700 to 900 casualties.