On September 1, 1862, an intense storm added to the violent sounds of the battle fought here as the Union army attempted to retreat after losing the Battle of Manassas a few days earlier. Two important Union generals, Isaac Stevens and Philip Kearney, were killed here. More than 2,100 soldiers were killed and wounded, but the battle did not change the outcome of the war. In 1860, 13% of the population of the United States were immigrants, and one in four Union soldiers were immigrants. The Confederate army also included immigrants of various nationalities, though little is known about them. Like many of the German-born soldiers who fought here, large numbers of Civil War soldiers could not read or speak English.