The Battle of Chantilly, also known as the Battle of Ox Hill, was a significant encounter during the Maryland Campaign of the American Civil War, occurring in the vicinity of Chantilly, Virginia. On September 1, Confederate Lieutenant General Thomas 'Stonewall' Jackson sought to capitalize on the disarray that had enveloped Union forces after their retreat from the recently concluded Second Battle of Bull Run. The Union troops, primarily under the command of Major General John Pope, were vulnerable as they regrouped across the area. As night fell, Jackson's men executed a surprise attack on the Union rear guard near dusk, aiming to disrupt their movement and eliminate the threat posed by their regrouping forces.The battle unfolded quickly, with the Confederates launching aggressive assaults against the Union lines. The Union soldiers, fighting in the darkness and amidst confusion, managed to offer stiff resistance but were ultimately outmaneuvered. Jackson's forces demonstrated effective use of their knowledge of the terrain, which played a decisive role in their success. The clash resulted in significant casualties, and many Union troops, realizing the situation was untenable, retreated further, eventually leading to their withdrawal across the Potomac River. This victory not only bolstered Confederate morale but also delaying Union plans for advancing into Maryland.