The Battle of Chantilly, also known as the Battle of Ox Hill, took place on September 1, 1862, during the American Civil War. It was fought between the Union forces, led by General John Pope, and the Confederate troops under General Stonewall Jackson. The battle occurred near Chantilly, Virginia, as the Union army was retreating after the defeat at the Second Battle of Bull Run. The engagement was marked by heavy rain and poor visibility, which complicated the fighting. Despite fierce combat, the Union forces managed to hold their ground and eventually withdrew in an organized manner. The battle resulted in significant casualties on both sides but did not change the overall strategic situation in the region.