The Battle of Bull Run, fought on July 21, 1861, was significant during the American Civil War as it marked the first major battle between the Union and Confederate forces. The Confederate victory shattered the North's hopes for a quick resolution to the war and showcased the South’s military capabilities. It demonstrated that the conflict would be longer and bloodier than anticipated. The battle also had psychological implications, bolstering Southern morale and leading to greater recruitment in the Confederate Army. Additionally, it prompted the Union to reassess its strategies, leading to a more prepared and mobilized approach in subsequent engagements.