Fought between Union and Confederate forces 160 years ago on August 28, 1862, the Battle of Thoroughfare Gap (aka Chapman’s Mill) in Fauquier and Prince William Counties, Virginia played a small but consequential role in ensuring Confederate victory in the Northern Virginia Campaign. Union Maj. Gen. John Pope missed an opportunity to isolate half of Robert E. Lee’s army and crush his legendary corps commander Thomas J. “Stonewall” Jackson.
The Northern Virginia Campaign is widely considered to be Confederate General Robert E. Lee’s most successful military campaign. It culminated in the Second Battle of Bull Run, in which an entire Union army was nearly destroyed. This paved the way for Lee’s invasion of Maryland and the Battle of Antietam, the bloodiest single day in American history. The Northern Virginia Campaign resulted in over 25,000 total casualties.
By late August 1862, Confederate Gen. Robert E. Lee’s Army of Northern Virginia, 50,000 strong, squared off against Union Maj. Gen. John Pope’s Army of Virginia, 51,000 strong, 40 miles from Washington, DC. Lee outmaneuvered Pope, sending Maj. Gen. Thomas J. “Stonewall” Jackson’s wing around Pope’s flank to destroy his supply depot at Manassas Junction. Confederate Maj. Gen. James Longstreet followed with the rest of the army. To reach Jackson, Longstreet had to pass through Thoroughfare Gap in the Bull Run Mountains.