The Second Battle of Bull Run, also known as the Second Battle of Manassas, was fought from August 28 to August 30, 1862, in Prince William County, Virginia, during the American Civil War. It was a major Confederate victory under General Robert E. Lee, who outmaneuvered and defeated Union forces led by Major General John Pope. The battle was marked by intense fighting and high casualties, with over 20,000 combined losses. Lee's success cleared the way for the Confederate invasion of the North, leading to the Maryland Campaign and the Battle of Antietam. The battle reinforced Southern momentum and was a significant setback for the Union war effort.